MB-7542 Fix unset revision number on deserialization

Change-Id: I18b1f478c3fed736e381ea1eb970d811b318d37d
Reviewed-on: http://review.couchbase.org/24001
Reviewed-by: Damien Katz <damien@couchbase.com>
Tested-by: Aaron Miller <apage43@ninjawhale.com>
Reviewed-by: Jin Lim <jin@couchbase.com>