Revert "Check libvirt connection URI"

This reverts commit 7d2bfa814030b952dc221e808b652e2d1b15bf3a.

The virsh command is running as sudo across TOCI, so that change is not
needed and it's causing TOCI to fail when running on the server-side
(TOCI Jenkins).

Change-Id: Id9991a4bb9ff7410a8963b2f7aa6efe622780382