Allow to attach the HMR server to an external http server

Reviewed By: BYK

Differential Revision: D6752279

fbshipit-source-id: 250255a3b1226f8aab6054e507cb3910cdcd6a85

Author: rafeca

local-cli/server/runServer.js

@@ -131,7 +131,7 @@ function runServer(
     attachWebsocketServer({
       httpServer: serverInstance,
       path: '/hot',
-      websocketServer: new HmrServer(packagerServer, reporter),
+      websocketServer: new HmrServer(packagerServer),
     });
 
     wsProxy = webSocketProxy.attachToServer(serverInstance, '/debugger-proxy');