cta-rmcd issues if `/dev/sg0` is missing

It looks like if /dev/sg0 device is missing one cannot launch cta-rmcd.

Indeed in https://gitlab.cern.ch/cta/CTA/-/blob/main/mediachanger/castorrmc/rmc/rmc_send_scsi_cmd.c#L144

Even if the specified device path is fine, this portion of the code:

                /* get the major device ID of the sg devices ... */
		if (stat ("/dev/sg0", &sbufa) < 0) {
			serrno = errno;
			snprintf (rmc_err_msgbuf, sizeof(rmc_err_msgbuf), "/dev/sg0 : stat error : %s\n", strerror(errno));
			rmc_err_msgbuf[sizeof(rmc_err_msgbuf) - 1] = '\0';
			*msgaddr = rmc_err_msgbuf;
			return (-1);
		}

exits from rmc_send_scsi_cmd if /dev/sg0 is missing.