Cleanup the disks.cfg file
Cleanup the disks.cfg file

The newly introduced disks.cfg file is still remaining in the
configuration folder after the sandbox is stopped. Let's remove it like
the other things there.

erenyagdiran/libvirt-sandbox,agx/libvirt-sandbox-debian,erenyagdiran/libvirt-sandbox,agx/libvirt-sandbox-debian,agx/libvirt-sandbox-debian,libvirt/libvirt-sandbox,libvirt/libvirt-sandbox,agx/libvirt-sandbox-debian,agx/libvirt-sandbox-debian,erenyagdiran/libvirt-sandbox,erenyagdiran/libvirt-sandbox,libvirt/libvirt-sandbox