dns_conf: Output log when configuration item is not supported

src/dns_conf.c

@@ -4177,6 +4177,11 @@ static int _conf_printf(const char *file, int lineno, int ret)
 		syslog(LOG_NOTICE, "process config file '%s' failed at line %d.", file, lineno);
 		return -1;
 		break;
+	case CONF_RET_NOENT:
+		tlog(TLOG_WARN, "unsupported config at '%s:%d'.", file, lineno);
+		syslog(LOG_NOTICE, "unsupported config at '%s:%d'.", file, lineno);
+		return -1;
+		break;
 	default:
 		break;
 	}

src/lib/conf.c

@@ -440,7 +440,6 @@ static int load_conf_file(const char *file, struct config_item *items, conf_erro
 			}
 
 			if (items[i].item == NULL) {
-				handler(file, line_no, CONF_RET_NOENT);
 				break;
 			}