MB-11724 announce config changes during the config upgrade
MB-11724 announce config changes during the config upgrade

...so they get replicated to the other nodes quickly

Change-Id: I3ac33ffa087401ea285da07c739054e8de2d4454
Reviewed-on: http://review.couchbase.org/39706
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,mschoch/ns_server,nimishzynga/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,mschoch/ns_server,mschoch/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,membase/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server