MB-8663 Switch to using xdc_settings.

Change-Id: Ic22be624fc62d0569b0d9f10784bc45122100a6e
Reviewed-on: http://review.couchbase.org/28185
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>