jira-inline-code: support comments in Jira Service Management

Jira Service Management is a companion product to regular Jira.[1]
Add support for inline code in comments on pages of Jira Service
Management to the user style jira-inline-code.user.css.

These comments are usually visible in the "Help Center", "Help Desk", or
"Help Portal" portion of Jira Service Management instanec.  These
portals are usually available on URLs like:

	https://jira.example.com/servicedesk/customer/portals

[1] https://www.atlassian.com/software/jira/service-management/product-guide/overview

jira-inline-code.user.css

@@ -8,7 +8,7 @@
 @preprocessor uso
 @var text yourDomain "Your Jira domain" "jira.example.com"
 @var text yourDomain2 "Your 2nd Jira domain" "jira.example.com"
-@version      14
+@version      15
 ==/UserStyle== */
 
 /*
@@ -37,6 +37,7 @@
 	#descriptionmodule tt,
 	.wiki-edit tt,
 	.flooded tt,
+	.activity-item tt,
 	.comment-item__action-body--container tt,
 	span.monospace,
 	.mce-content-body tt,