Remove temporary client

This patch removes a temporary client needed to transition the
neutron-tempest-plugin test_dns_integration over to the tempest
registry.

Depends-On: https://review.opendev.org/c/openstack/neutron-tempest-plugin/+/800291
Change-Id: I26da94382b8a66509e2294ffbb3b282847b2c0d0
2 files changed