Replace obsolete <center> element with <p class="text-center"> (letse…

…ncrypt#927)

The class "text-center" is defined as "text-align: center;"
https://developer.mozilla.org/fr/docs/Web/HTML/Element/center

content/de/docs/ct-logs.html

@@ -15,7 +15,7 @@ <h2>Finanzierung</h2>
 
 <p>Wir möchten folgenden Partnern für die grossartige Unterstützung von Let's Encrypt CT Log danken. Wenn Ihre Organisation helfen möchte, diese Arbeit fortzusetzen, bitte besuchen Sie <a href="{{< relref "/become-a-sponsor" >}}">Sponsor werden</a>.</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>Architektur</h2>
 

content/en/docs/ct-logs.html

@@ -19,7 +19,7 @@ <h2>Funding</h2>
 
 <p>We'd like to thank the following partners for generously sponsoring the Let's Encrypt CT log. If your organization would like to help us continue this work, please consider <a href="{{< relref "/become-a-sponsor" >}}">sponsoring or donating</a>.</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>Architecture</h2>
 

content/en/post/2016-4-12-leaving-beta-new-sponsors.markdown

@@ -13,7 +13,7 @@ Let’s Encrypt is leaving beta today. We’re also excited to announce that fou
 
 Since our beta began in September 2015 we’ve issued more than 1.7 million certificates for more than 3.8 million websites. We’ve gained tremendous operational experience and confidence in our systems. The beta label is simply not necessary any more.
 
-<center><img src="/images/Issuance-April-10-2016.png" alt="Issuance as of April 10, 2016" style="width: 650px; margin-bottom: 17px;"/></center>
+<p class="text-center"><img src="/images/Issuance-April-10-2016.png" alt="Issuance as of April 10, 2016" style="width: 650px; margin-bottom: 17px;"/></p>
 
 We set out to encrypt 100% of the Web. We’re excited to be off to a strong start, and with so much support across the industry.
 

content/en/post/2016-6-22-https-progress-june-2016.markdown

@@ -11,7 +11,7 @@ Our goal with Let’s Encrypt is to get the Web to 100% HTTPS. We’d like to gi
 
 Let’s Encrypt has issued more than 5 million certificates in total since we launched to the general public on December 3, 2015. Approximately 3.8 million of those are active, meaning unexpired and unrevoked. Our active certificates cover more than 7 million unique domains.
 
-<center><img src="/images/le-certs-issued-june-22-2016.png" alt="Issuance as of June 22, 2016" style="width: 650px; margin-bottom: 17px;"/></center>
+<p class="text-center"><img src="/images/le-certs-issued-june-22-2016.png" alt="Issuance as of June 22, 2016" style="width: 650px; margin-bottom: 17px;"/></p>
 
 A couple of different factors have contributed heavily to this growth. The first is large-scale deployments from companies such as OVH, WordPress.com, Akamai, Shopify, Dreamhost, and Bitly. The second is our ability to serve individual sites globally with a focus on ease-of-use. If we’re going to get to 100% HTTPS we need to reach the “long tail” of the Web, which is in many ways more challenging due to the number of parties involved and widely varying degrees of technical competency.
 

content/en/post/2016-8-5-le-root-to-be-trusted-by-mozilla.markdown

@@ -13,7 +13,7 @@ Public CAs need their certificates to be trusted by browsers and devices. CAs th
 
 Getting a new root trusted and propagated broadly can take 3-6 years. In order to start issuing widely trusted certificates as soon as possible, we partnered with another CA, IdenTrust, which has a number of existing trusted roots. As part of that partnership, an IdenTrust root “vouches for” the certificates that we issue, thus making our certificates trusted. We’re incredibly grateful to IdenTrust for helping us to start carrying out our mission as soon as possible.
 
-<center><p><img src="/images/le-firefox-chain-of-trust.png" alt="Chain of trust between Firefox and Let's Encrypt certificates." style="width: 650px; margin-bottom: 17px;"/><br><em>Chain of Trust Between Firefox and Let's Encrypt Certificates</em></p></center>
+<p class="text-center"><img src="/images/le-firefox-chain-of-trust.png" alt="Chain of trust between Firefox and Let's Encrypt certificates." style="width: 650px; margin-bottom: 17px;"/><br><em>Chain of Trust Between Firefox and Let's Encrypt Certificates</em></p>
 
 However, our plan has always been to operate as an independently trusted CA. Having our root trusted directly by the Mozilla root program represents significant progress towards that independence.
 

content/en/post/2017-1-6-le-2016-in-review.markdown

@@ -12,7 +12,7 @@ Our first full year as a live CA was an exciting one. I’m incredibly proud of
 
 At the start of 2016, Let’s Encrypt certificates had been available to the public for less than a month and we were supporting approximately 240,000 active (unexpired) certificates. That seemed like a lot at the time! Now we’re frequently issuing that many new certificates in a single day while supporting more than 20,000,000 active certificates in total. We’ve issued more than a million certificates in a single day a few times recently. We’re currently serving an average of 6,700 OCSP responses per second. We’ve done a lot of optimization work, we’ve had to add some hardware, and there have been some long nights for our staff, but we’ve been able to keep up and we’re ready for another year of [strong growth](https://letsencrypt.org/stats/).
 
-<center><p><img src="/images/Jan-6-2017-Cert-Stats.png" alt="Let's Encrypt certificate issuance statistics." style="width: 650px; margin-bottom: 17px;"/></p></center>
+<p class="text-center"><img src="/images/Jan-6-2017-Cert-Stats.png" alt="Let's Encrypt certificate issuance statistics." style="width: 650px; margin-bottom: 17px;"/></p>
 
 We added a number of [new features](https://letsencrypt.org/upcoming-features/) during the past year, including support for the ACME DNS challenge, ECDSA signing, IPv6, and Internationalized Domain Names.
 

content/en/post/2017-6-28-hundred-million-certs.markdown

@@ -17,7 +17,7 @@ Third, it illustrates the power of automated certificate management. If getting
 
 The total number of certificates we’ve issued is an interesting number, but it doesn’t reflect much about tangible progress towards our primary goal: a 100% HTTPS Web. To understand that progress we need to look at this graph:
 
-<center><p><img src="/images/2017.06.28-https-percentage.png" alt="Percentage of HTTPS Page Loads in Firefox." style="width: 650px; margin-bottom: 17px;"/></p></center>
+<p class="text-center"><img src="/images/2017.06.28-https-percentage.png" alt="Percentage of HTTPS Page Loads in Firefox." style="width: 650px; margin-bottom: 17px;"/></p>
 
 When Let’s Encrypt’s service first became available, less than 40% of page loads on the Web used HTTPS. It took the Web 20 years to get to that point. In the 19 months since we launched, encrypted page loads have gone up by 18%, to nearly 58%. That’s an incredible rate of change for the Web. Contributing to this trend is what we’re most proud of.
 

content/es/docs/ct-logs.html

@@ -15,7 +15,7 @@ <h2>Fondos</h2>
 
 <p>Nos gustaría agradecer a los siguientes socios por patrocinar generosamente el registro CT de Let's Encrypt. Si su organización desea ayudarnos a continuar este trabajo, por favor considere <a href="{{< ref "/become-a-sponsor" >}}">patrocinar o donar</a>.</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>Arquitectura</h2>
 

content/ja/docs/ct-logs.html

@@ -15,7 +15,7 @@ <h2>ファンディング</h2>
 
 <p>Let's Encrypt の CT ログを寛大に支援してくれている以下のパートナーに感謝します。私たちがこの仕事を継続できるよう、もしあなたの組織が支援してくれるなら、ぜひ<a href="{{< relref "/become-a-sponsor" >}}">スポンサーになる、または、寄付する</a>ことを検討してください。よろしくお願いします。</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>アーキテクチャ</h2>
 

content/ko/docs/ct-logs.html

@@ -18,9 +18,7 @@ <h2>펀딩</h2>
 <p>Let's Encrypt CT 로그를 후하게 후원해 주신 다음 파트너 여러분께 감사드립니다. 귀사에서 이 작업을 계속하는 데 도움을 받으려면 다음 사항을 고려하시기 바랍니다.<a
         href="{{< relref "/become-a-sponsor" >}}">후원 또는 기부</a>.</p>
 
-<p>
-    <center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center>
-</p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>구조</h2>
 

content/ru/docs/ct-logs.html

@@ -15,7 +15,7 @@ <h2>Финансирование</h2>
 
 <p>Мы хотели бы поблагодарить наших партнеров за щедрую финансировую поддержку нашего журнала CT. Если Ваша организация хотела бы помочь нам продолжить эту работу, <a href="{{< relref "/become-a-sponsor" >}}">пожалуйста станьте нашим спонсором или дарителем</a>.</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>Архитектура</h2>
 

content/zh-cn/docs/ct-logs.html

@@ -17,7 +17,7 @@ <h2>资金来源</h2>
 
 <p>我们要感谢以下合作伙伴慷慨赞助 Let's Encrypt 的 CT 日志。如果您的组织希望帮助我们继续这项工作，请考虑<a href="{{< relref "/become-a-sponsor" >}}">捐赠或成为赞助商</a>。</p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>架构</h2>
 

content/zh-tw/docs/ct-logs.html

@@ -15,7 +15,7 @@ <h2>資金來源</h2>
 
 <p>我們要感謝這些的夥伴慷慨地贊助 Let's Encrypt 的憑證透明度系統。如果你的組織想幫助我們繼續這項工作，請參考<a href="{{< relref "/become-a-sponsor" >}}">捐贈或成為贊助商</a></p>
 
-<p><center><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></center></p>
+<p class="text-center"><a href="https://sectigo.com/"><img src="/images/sectigo_logo_color.svg" width="240" alt="Sectigo"></a></p>
 
 <h2>架構</h2>