Avoid a query if enabled_modules association is already loaded (#15058).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@12228 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -961,7 +961,7 @@ class Project < ActiveRecord::Base
 
   def allowed_permissions
     @allowed_permissions ||= begin
-      module_names = enabled_modules.pluck(:name)
+      module_names = enabled_modules.loaded? ? enabled_modules.map(&:name) : enabled_modules.pluck(:name)
       Redmine::AccessControl.modules_permissions(module_names).collect {|p| p.name}
     end
   end