pin port to fix facebook#147

Author: zangrafx

packages/react-dev-utils/webpackHotDevClient.js

@@ -162,7 +162,7 @@ var connection = new SockJS(
   url.format({
     protocol: window.location.protocol,
     hostname: window.location.hostname,
-    port: window.location.port,
+    port: 3000,
     // Hardcoded in WebpackDevServer
     pathname: '/sockjs-node',
   })