Update workaround for pbr >= 0.11
Update workaround for pbr >= 0.11

Now, it should supports more operators

Change-Id: I19a1149785161da9b4bca6e6f394debf4bd5d986

openstack-packages/delorean,openstack-packages/delorean,openstack-packages/DLRN,openstack-packages/DLRN