Remove copyright headers

src/app/app.module.ts

@@ -1,6 +1,3 @@
-// Copyright (C) 2018 Avatao.com Innovative Learning Kft.
-// All Rights Reserved. See LICENSE file for details.
-
 import { HttpClientModule } from '@angular/common/http';
 import { FormsModule } from '@angular/forms';
 import { BrowserModule } from '@angular/platform-browser';