message: Fix webpack dev server config warning.
diff: @@ -80,7 +80,7 @@ module.exports = function(proxy, allowedHost) {
  },
  public: allowedHost,
  proxy,
  - setup(app) {
  + before(app) {
  // This lets us open files from the runtime error overlay.
  app.use(errorOverlayMiddleware());
  