tooz: do not run py35-etcd3* on Ocata
tooz: do not run py35-etcd3* on Ocata

The rules are properly written, but as order matters, py35-etcd3* jobs are
currently run on Ocata whereas they do not exist in tox.

Changing the order of the rules should make sure we don't run those tests on
Ocata.

Change-Id: Ia9120f1ca750ef28265d00e4b83e1061d1b5b718

openstack-infra/project-config,openstack-infra/project-config