[rel-2.5.0] bumped ns_server reference for MB-9988

Change-Id: I2855acb3d4113330c4d128e65ae1d7b9b606d1d3
[rel-2.5.0] bumped ns_server reference for MB-9988

Change-Id: Iabac462bed738cf7a5a6fd7da03b38eb690d4c54
Reviewed-on: http://review.couchbase.org/32759
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>