Revert "Stop devtest if user was not in libvirtd group"

This reverts commit 3690dcb9933c13dac6cc680dcb13f0db107d63ad.

The prior behaviour does work on Ubuntu and was crucial for CI to
work. This commit broke CI and should not have been merged.

Change-Id: I6a333820d495e8337931ba5cc663aeaafda7fb53