Fix EZP-22915: do not use $rootCheck when clearing globlal ini cache

49583e introduced an "egg or chicken" dilemma : when you use ezcache.php to clear the global ini cache, eZDir::recursiveDelete() will read the old settings from the cache, and may disallow you to clear the cache if your old settings disallow it.

https://jira.ez.no/browse/EZP-22915
PR: #981