removed unused imports

Frontend/src/components/App.js

@@ -1,6 +1,6 @@
 import React, { Component } from "react";
 import CssBaseline from "@material-ui/core/CssBaseline";
-import { BrowserRouter as Router, Route, Link } from "react-router-dom";
+import { BrowserRouter as Router, Route } from "react-router-dom";
 import Login from "./Login.js";
 import { Box } from "@material-ui/core";
 import Aufnahmeantrag from "./Aufnahmeantrag.js";

Frontend/src/components/Login.js

@@ -1,6 +1,5 @@
 import React, { Component } from "react";
 import TextField from "@material-ui/core/TextField";
-import Grid from "@material-ui/core/Grid";
 
 class Login extends Component {
   state = {};