Updated openstack/openstack
Project: openstack-infra/devstack-gate  6c529a69d4b9c53b3a93ea09bc5500fefef4f51b
null
Add ZUUL_PROJECT to periodic test

To demonstrate that it is now safe to not unset it (because the
ZUUL_REF checkout check has been removed).

Change-Id: I4f88485fa2f9307ce80e0dd845f865e60c22f9f6