Ticket 49734 - Fix various issues with Disk Monitoring
    
    Bug Description:  The first issue what the internal represenation of
                      the default error code changed since the feature was
                      added.  This caused the disk monitoring thread to loop
                      and never actually attempt to stop the server.  The
                      other issue is that with nunc-stans g_set_shutdown()
                      is no longer stops the server.
    
    Fix Description:  Change the defaulterror logging level to be more robust
                      and accept all the default level values.  Also, we needed
                      to free the rotated logs when we delete them.  Finally
                      add raise() to g_set_downdow(), and make sure set_shutdown()
                      does not overwrite the slapd_shutdown value.
    
    https://pagure.io/389-ds-base/issue/49734
    
    Reviewed by: tbordaz & spichugi(Thanks!)