Update Cross_Site_Scripting_Prevention_Cheat_Sheet.md to remove dupli…

…cate wording

Removing duplicate wording.

cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.md

@@ -26,7 +26,7 @@ When you use a modern web framework, you need to know how your framework prevent
 
 ## XSS Defense Philosophy
 
-In order for an XSS attack to be successful, an attacker must be able to to insert and execute malicious content in a webpage. Thus, all variables in a web application needs to be protected. Ensuring that **all variables** go through validation and are then escaped or sanitized is known as **perfect injection resistance**. Any variable that does not go through this process is a potential weakness. Frameworks make it easy to ensure variables are correctly validated and escaped or sanitised.
+In order for an XSS attack to be successful, an attacker must be able to insert and execute malicious content in a webpage. Thus, all variables in a web application needs to be protected. Ensuring that **all variables** go through validation and are then escaped or sanitized is known as **perfect injection resistance**. Any variable that does not go through this process is a potential weakness. Frameworks make it easy to ensure variables are correctly validated and escaped or sanitised.
 
 However, no framework is perfect and security gaps still exist in popular frameworks like React and Angular. Output encoding and HTML sanitization help address those gaps.