MB-12028: [rel-3.0.0] updated ns_server reference

Change-Id: Ie8bcef9f9fc63d98b32ffcec3b4568a56ca112c9
Reviewed-on: http://review.couchbase.org/40733
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>