Disregard expire methods when the controller hasnt been set, which essentially makes it such that the record observer callbacks are ignored when the sweeper shouldnt be active

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1242 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_controller/caching.rb

@@ -469,6 +469,7 @@ module ActionController #:nodoc:
           end
         
           def method_missing(method, *arguments)
+            return if @controller.nil?
             @controller.send(method, *arguments)
           end
       end