MB-5307 Replace ns_config:search by search_quick.

On my microbenchmark search_quick worked about 4 times faster.

Change-Id: Ie86770a7d635eea2661b123bd261927a83e82fc5
Reviewed-on: http://review.couchbase.org/25236
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>