Don't show the "advanced-cache.php warning" when the plugin isn't loaded, props RobertHarm, http://wordpress.org/support/topic/wp-super-cache-breaks-leaflet-maps-marker-plugin


git-svn-id: https://plugins.svn.wordpress.org/wp-super-cache/trunk@803002 b8457f37-d9ea-0310-8a92-e5e31aec5664