Error message is not useful if VM IP address cannot be detected

[Robie Basak]

danwest@x1:~$ uvt-kvm ssh host2 --insecure
Traceback (most recent call last):
  File "/usr/bin/uvt-kvm", line 35, in <module>
    uvtool.libvirt.kvm.main_cli_wrapper(sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 709, in main_cli_wrapper
    main(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 704, in main
    args.func(parser, args)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 580, in main_ssh
    return ssh(name, login_name, args.ssh_arguments)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 471, in ssh
    ip = ips[0]
IndexError: list index out of range

Expected result: some error along the lines of "Cannot determine IP address of host2".