Fix UKI image repos in fedora-cloud.conf
    
    These should be the same as every other image here, looks like
    this was copied from fedora.conf without being adjusted. Note
    this config is never used on this branch, but it is the base for
    new release branches so we should keep it correct.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>