Fix regex for Designate
Fix regex for Designate

As of now the Designate job is running both
designate-tempest-plugin and tempest-plugin tests.
The latter is not needed.

This patch fixes the regex for the designate.yml
file, so it runs only designate-tempest-plugin.

Change-Id: I567bdc241569bb18b7ac8389d0211ba0932fe6a0

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared