Updating connection's state regardless of listener

 - This fixes the logs seen in https://github.com/mrniko/redisson/issues/87
 - Makes sure the pubsub connection is kept in the proper state, regardless
    of the order in which to clients decide to operate
    (unsubscribe / removelistener)

This is a definitive fix for https://github.com/mrniko/redisson/issues/87 and keeps the connection state always sane.