frontend: fix rawhide_to_release/brach_fedora commands
    
    Traceback (most recent call last):
      File "/usr/bin/copr-backend-process-action", line 35, in handle_action
        result = action.run()
      File "/usr/lib/python3.9/site-packages/copr_backend/actions.py", line 421, in run
        appstream = data["appstream"]
    KeyError: 'appstream'
    
    Follow up for: 3c765a95f21448e28a8d41b6655f89a1c126c426