CBLT-283:  fix up link_to_package() for sync_gateway

Change-Id: Ic11fa68686a3c3ec50d0a2dcf79ce58789db4677
Reviewed-on: http://review.couchbase.org/36858
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>