Merged r20665 from trunk to 4.0-stable (#34461).

git-svn-id: http://svn.redmine.org/redmine/branches/4.0-stable@20668 e93f8b46-1217-0410-a6f0-8f06a7374b81

Gemfile

@@ -43,7 +43,7 @@ platforms :mri, :mingw, :x64_mingw do
 
   # Optional Markdown support, not for JRuby
   group :markdown do
-    gem "redcarpet", "~> 3.5.0"
+    gem 'redcarpet', '~> 3.5.1'
   end
 end