update nodejs to use the var serverport

Author: wing328

modules/swagger-codegen/src/main/resources/nodejs/index.mustache

@@ -31,8 +31,8 @@ swaggerTools.initializeMiddleware(swaggerDoc, function (middleware) {
   app.use(middleware.swaggerUi());
 
   // Start the server
-  http.createServer(app).listen({{serverPort}}, function () {
-    console.log('Your server is listening on port %d (http://localhost:%d)', {{serverPort}}, {{serverPort}});
-    console.log('Swagger-ui is available on http://localhost:%d/docs', {{serverPort}});
+  http.createServer(app).listen(serverPort, function () {
+    console.log('Your server is listening on port %d (http://localhost:%d)', serverPort, serverPort);
+    console.log('Swagger-ui is available on http://localhost:%d/docs', serverPort);
   });
-});
+});