Switch neutron-tempest-plugin-api job to be ML2/OVS

It will give us more API tests coverage as we don't need to e.g.
skip logging tests, even when Devstack will be switched to the ML2/OVN
backend.
It also enables deploying Neutron with uwsgi again, as with ML2/OVS
backend it isn't broken.

Change-Id: I90f3c430504677a42e98230b84ea87f863c1331b
Closes: #1928345
1 file changed