test: Fix image names in check-machines-dbus
test: Fix image names in check-machines-dbus

The test was meaning to exclude rhel-8-{0,1}. It only works sometimes as
the test gets skipped through a naughty.

mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit,garrett/cockpit,cockpit-project/cockpit,cockpituous/cockpit,garrett/cockpit,cockpituous/cockpit,cockpituous/cockpit,martinpitt/cockpit,deryni/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,martinpitt/cockpit,cockpituous/cockpit,martinpitt/cockpit,cockpituous/cockpit,martinpitt/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,garrett/cockpit,deryni/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,garrett/cockpit,deryni/cockpit,deryni/cockpit,garrett/cockpit,moraleslazaro/cockpit,deryni/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,deryni/cockpit,deryni/cockpit,cockpit-project/cockpit