Use openstack_service_workers variable in gate
Use openstack_service_workers variable in gate

set openstack_service_workers to 1 in gate.

Closes-Bug: #1640416
Change-Id: I59560fd543f25e0b60b3f11f1c941adf595b3131

stackforge/kolla,stackforge/kolla,GalenMa/kolla,mrangana/kolla,dardelean/kolla-ansible,coolsvap/kolla,GalenMa/kolla,mrangana/kolla,nihilifer/kolla,openstack/kolla,intel-onp/kolla,rahulunair/kolla,openstack/kolla,dardelean/kolla-ansible,rahulunair/kolla,coolsvap/kolla,nihilifer/kolla,dardelean/kolla-ansible,coolsvap/kolla,intel-onp/kolla,stackforge/kolla