CBLT-283:  fix up link_to_package() for sync_gateway

Change-Id: I19f22c03dbf93f12d38875d2b4ff6932b3459095
Reviewed-on: http://review.couchbase.org/36859
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>