MB-8663 Use type from replicator document to decide on rep mode.

Change-Id: Ia856cdbacfefc25179e8d26af7083a6a94a626ee
Reviewed-on: http://review.couchbase.org/28171
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>