Fix detection of KRA installation so upgrades can succeed
    
    Use is_installed() instead of is_configured() because
    is_installed() does a config file check to see if the service
    is in use.
    
    https://pagure.io/freeipa/issue/7389
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>