refine the config code.

@@ -1337,8 +1337,8 @@ int SrsConfig::check_config()
             && n != "max_connections" && n != "daemon" && n != "heartbeat"
             && n != "http_api" && n != "stats" && n != "vhost" && n != "pithy_print_ms"
             && n != "http_stream" && n != "http_server" && n != "stream_caster"
-            && n != "utc_time")
-        {
+            && n != "utc_time"
+        ) {
             ret = ERROR_SYSTEM_CONFIG_INVALID;
             srs_error("unsupported directive %s, ret=%d", n.c_str(), ret);
             return ret;