http: describe parse err in debug output

Backport-PR-URL: #14416
PR-URL: #13206
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>

Author: sam-github

lib/_http_client.js

@@ -361,7 +361,7 @@ function socketOnData(d) {
 
   var ret = parser.execute(d);
   if (ret instanceof Error) {
-    debug('parse error');
+    debug('parse error', ret);
     freeParser(parser, req, socket);
     socket.destroy();
     req.emit('error', ret);

lib/_http_server.js

@@ -379,7 +379,7 @@ function connectionListener(socket) {
 
   function onParserExecuteCommon(ret, d) {
     if (ret instanceof Error) {
-      debug('parse error');
+      debug('parse error', ret);
       socketOnError.call(socket, ret);
     } else if (parser.incoming && parser.incoming.upgrade) {
       // Upgrade or CONNECT