approvers: remove "you haven't moderated in awhile" notice.

Remove the nag message when an approver hasn't approved anything
recently. Also remove the modqueue random posts page. As of 3d410398a,
inactive approvers are now warned via dmails.

test/functional/moderator/post/queues_controller_test.rb

@@ -18,13 +18,6 @@ module Moderator
             assert_response :success
           end
         end
-
-        context "random action" do
-          should "render" do
-            get_auth moderator_post_queue_path, @admin
-            assert_response :success
-          end
-        end
       end
     end
   end