Rails3: use String#html_safe at lib/redmine/helpers/diff.rb.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@6472 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine/helpers/diff.rb

@@ -65,7 +65,7 @@ module Redmine
             words_del = 0
           end
         end
-        words.join(' ')
+        words.join(' ').html_safe
       end
     end
   end