have --open use the options.public path if it exists

Author: bdwain

bin/webpack-dev-server.js

@@ -196,7 +196,7 @@ if(options.inline) {
 }
 
 new Server(webpack(wpOpt), options).listen(options.port, options.host, function(err) {
-	var uri = protocol + "://" + options.host + ":" + options.port + "/";
+	var uri = protocol + "://" + (options.public || (options.host + ":" + options.port)) + "/";
 	if(!options.inline)
 		uri += "webpack-dev-server/";