MB-7542 Fix unset revision number on deserialization

Change-Id: I18b1f478c3fed736e381ea1eb970d811b318d37d
Reviewed-on: http://review.couchbase.org/24000
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>