Validate the Directory Manager password before starting restore
    
    The password was only indirectly validated when trying to
    disable replication agreements for the restoration.
    
    Only validate the password if the IPA configuration is available
    and dirsrv is running.
    
    https://pagure.io/freeipa/issue/7136
    https://pagure.io/freeipa/issue/7535
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>