Rails3: use String#html_safe for render_descendants_tree() at IssuesHelper.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@6497 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/helpers/issues_helper.rb

@@ -87,7 +87,7 @@ module IssuesHelper
              :class => "issue issue-#{child.id} hascontextmenu #{level > 0 ? "idnt idnt-#{level}" : nil}")
     end
     s << '</form></table>'
-    s
+    s.html_safe
   end
 
   def render_custom_fields_rows(issue)