Accept --no-config option to inhibit loading default config file, even without specifying another config

miner.c

@@ -2581,6 +2581,9 @@ static struct opt_table opt_cmdline_table[] = {
 		     load_config, NULL, NULL,
 		     "Load a JSON-format configuration file\n"
 		     "See example.conf for an example configuration."),
+	OPT_WITHOUT_ARG("--no-config",
+	                opt_set_bool, &config_loaded,
+	                "Inhibit loading default config file"),
 	OPT_WITHOUT_ARG("--help|-h",
 			opt_verusage_and_exit, NULL,
 			"Print this message"),