Fix compatibility with tempest project

Cli tempest test that tests answer for nonexistent
command fails due to change in tempest, see:
https://github.com/openstack/tempest/commit/7a2cf01f8b629c5b40def151780ddadb6d9d3416

Made same changes for manila test.

Change-Id: Ic863c1f232f17b04a8a914ee01dc14e84a458806