Skip secgroup invalid name/desc tests until bug 1161411 is fixed

There is an existing review which tries to deal with bug 1161411:

https://review.openstack.org/#/c/34559/

Until there is consensus on how to fix this, skip the compute tests if
neutron is available.

Change-Id: I41bd2232ad4e489daaa8de3902d7e158f3e577bf
Merge "Skip secgroup invalid name/desc tests until bug 1161411 is fixed"