Comment 2 for bug 1419723

My previous comment could be understood incorrectly. What I meant is that if you have such error the problem could be in test itself, when it is running in more than one thread, try to create more than one default security group in one tenant, that is not allowed. There is https://bugs.launchpad.net/tempest/+bug/1416294 bug for check-grenade-dsvm-neutron.