[#34044] xcache not working under J3.3.3

### Why we need this spezial test?

In some envoirments ini_get('xcache.admin.enable_auth') is off but return empty. 

### Tracker
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=34044