Quota shows a VM being used when there are none listed

[jrha]

@apdibbo tells me that this is because Openstack has not updated it's quotas internally after a stuck VM has been forcibly removed from the system, so this is not strictly a web interface bug. But it might be a nice idea to cross check the number of VMs listed versus what the quota is reporting and warn the user that something strange is happening if they differ.