Allow giving alphanumeric channels (Prepare for IMTS)

src/jolly/main.c

@@ -196,7 +196,7 @@ int main(int argc, char *argv[])
 			fprintf(stderr, "Failed to create transceiver instance. Quitting!\n");
 			goto fail;
 		}
-		printf("base station on channel %d ready, please tune transmitter to %.4f MHz and receiver to %.4f MHz. (%.4f MHz offset)\n", kanal[i], dl_freq + step / 1e3 * (double)kanal[i], ul_freq + step / 1e3 * (double)kanal[i], ul_freq - dl_freq);
+		printf("base station on channel %s ready, please tune transmitter to %.4f MHz and receiver to %.4f MHz. (%.4f MHz offset)\n", kanal[i], dl_freq + step / 1e3 * (double)atoi(kanal[i]), ul_freq + step / 1e3 * (double)atoi(kanal[i]), ul_freq - dl_freq);
 	}
 
 	main_mobile(&quit, latency, interval, NULL, station_id, 4);