Only attempt to upgrade ACME configuration files if deployed
    
    This can happen on upgrades from older deployments that lack
    an ACME installation and don't meet the minimum requirements
    to deploy one automatically.
    
    Also don't consider missing ACME schema a total failure, just
    log and skip it.
    
    https://pagure.io/freeipa/issue/8832
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>