Update ep_engine branch in toy-junyi.xml

Change-Id: I8f902c853cf8c2e5da7b34ca27b255976cfa84d0
Reviewed-on: http://review.couchbase.org/26447
Reviewed-by: Junyi Xie <junyi.couchbase@gmail.com>
Tested-by: Junyi Xie <junyi.couchbase@gmail.com>