test: Fix flake in check-realms
test: Fix flake in check-realms

`testIpaUnqualifiedUsers` reboots, but forgot to allow the corresponding
messages. Fixes this failure:

```
Error: org.freedesktop.PackageKit: couldn't get all properties of org.freedesktop.PackageKit.Transaction at /5_beedcbdc: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
```

Closese #9559
mvollmer/cockpit,garrett/cockpit,andreasn/cockpit,martinpitt/cockpit,andreasn/cockpit,cockpit-project/cockpit,deryni/cockpit,cockpit-project/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,cockpituous/cockpit,garrett/cockpit,moraleslazaro/cockpit,mareklibra/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,deryni/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpituous/cockpit,martinpitt/cockpit,mareklibra/cockpit,deryni/cockpit,mareklibra/cockpit,mareklibra/cockpit,deryni/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,andreasn/cockpit,cockpituous/cockpit,deryni/cockpit,andreasn/cockpit,andreasn/cockpit,moraleslazaro/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,garrett/cockpit,moraleslazaro/cockpit,deryni/cockpit,andreasn/cockpit,mvollmer/cockpit,cockpituous/cockpit,cockpit-project/cockpit,andreasn/cockpit,garrett/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,mareklibra/cockpit,moraleslazaro/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,mvollmer/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,martinpitt/cockpit,mvollmer/cockpit,mareklibra/cockpit