Only use 'state_listener' if configuration has changed

This screws up some of our tests otherwise..

Change-Id: I55ffc9f233a999466b1fabdeaa8f529f1001a5a4
Reviewed-on: http://review.couchbase.org/31824
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>