Fix ep-engine repository in toy-junyi.xml

Change-Id: Ib8c9b6ad89f3d562c48259e7eb2eda67d41edaa2
Reviewed-on: http://review.couchbase.org/25098
Reviewed-by: Junyi Xie <junyi.couchbase@gmail.com>
Tested-by: Junyi Xie <junyi.couchbase@gmail.com>