MB-23138 Increase ns_cluster:change_address timeout.
MB-23138 Increase ns_cluster:change_address timeout.

Because on under-provisioned systems it may take longer than 5
seconds.

Change-Id: Ib80387deba3a8f0117d95a5a2d83f9fc6b3451cb
Reviewed-on: http://review.couchbase.org/74726
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Dave Finlay <7b10a9ed9f70e64c30b07607a671ae61c33f14c8@couchbase.com>

ceejatec/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,ceejatec/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server