[webui] Replace a find with a find_cached...

src/webui/app/models/project.rb

@@ -405,7 +405,7 @@ def maintenance_incidents(type = 'open')
       when 'open' then predicate += " and repository/releasetarget/@trigger='maintenance'"
       when 'closed' then predicate += " and not(repository/releasetarget/@trigger='maintenance')"
     end
-    return Collection.find(:what => 'project', :predicate => predicate).each
+    return Collection.find_cached(:what => 'project', :predicate => predicate).each
   end
 
   def patchinfo