refactor(main.browser.ts): remove unused import (PatrickJS#976)

Author: avoyage

src/main.browser.ts

@@ -3,7 +3,6 @@
  */
 import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
 import { decorateModuleRef } from './app/environment';
-import { ApplicationRef } from '@angular/core';
 import { bootloader } from '@angularclass/hmr';
 /*
  * App Module