remove unnecessary log

lib/response.js

@@ -64,7 +64,6 @@ module.exports = function(request, response, result) {
     // handle etag caching
     var incoming_etag = request.headers["if-none-match"];
     if (incoming_etag && incoming_etag === headers.Etag) {
-      logging.debug(request.id, "Etag matches");
       response.writeHead(304, headers);
       response.end();
       return;