[desktop] Remove /desktop/debug/who_am_i

This is unused, and could be used by a malicious user to hang hue.
[core] Add config check to validate MySql storage engine
HUE-2467 [sentry] Disallow admin operations on parent page of prefixed directories

Applying on the list of files the permissions instead of only whithin the
prefixed files. That way we blaclist the prefixes accordingly in their parent dir.