OF-1901: Pubsub: stop allowing everyone to unsubscribe anyone
This commit removes a condition that appears to evaluate to 'true' always. This resuls in the permission-check to be overly permissive.
OF-1901: pubsub: compare bare JIDs while checking unsubscribe auth
To verify if a JID can issue an pubsub-unsubscribe for a (potentially other) JID, both JIDs should be compared based on their bare JID representation.
