test: Fix failures for unexpected virt-host-validate qemu

[martinpitt]

For a few months now, the RHEL downstream gating tests for cockpit-machines have all failed like this:

  File "/source/test/machineslib.py", line 38, in waitPageInit
    virtualization_enabled = "PASS" in self.machine.execute("virt-host-validate qemu | grep 'Checking for hardware virtualization'")
subprocess.CalledProcessError

The actual output shows

QEMU: Checking if device '/dev/kvm' exists: FAIL

and no "hardware virtualization" at all, which makes the grep fail. Treat an absent line as "fail".

[packit-as-a-service]

We were not able to find or create Copr project packit/cockpit-project-cockpit-machines-1760 specified in the config with the following error:

Packit received HTTP 500 Internal Server Error from Copr Service. Check the Copr status page: https://copr.fedorainfracloud.org/status/stats/, or ask for help in Fedora Build System matrix channel https://matrix.to/#/#buildsys:fedoraproject.org.

---

Unless the HTTP status code above is >= 500, please check your configuration for:

1. typos in owner and project name (groups need to be prefixed with @)
2. whether the project name doesn't contain not allowed characters (only letters, digits, underscores, dashes and dots must be used)
3. whether the project itself exists (Packit creates projects only in its own namespace)
4. whether Packit is allowed to build in your Copr project
5. whether your Copr project/group is not private

[martinpitt]

OK, that's the second try after #1759, I accept defeat -- no Fedora COPR today..

[mvollmer]

Thanks!