don't warn about closed connections

lib/response.js

@@ -36,10 +36,6 @@ module.exports = function(request, response, result) {
     "Access-Control-Allow-Origin": "*",
   };
 
-  response.on("close", function() {
-    logging.warn(request.id, "Connection closed");
-  });
-
   response.on("finish", function() {
     logging.log(request.id, request.method, request.url.href, response.statusCode, headers["Response-Time"] + "ms", "(" + (human_status[result.status] || "-") + ")");
   });