Keep config uuid in dynamic config.

Change-Id: Iebc7ca887edcb7131015a29cf20e9448576b5cba
Reviewed-on: http://review.couchbase.org/36027
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>