MB-12222: finalize cluster settings section

Change-Id: Ib425da45b5dbad176f1039da309f02e8b2097616
Reviewed-on: http://review.couchbase.org/42123
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>