Remove unused variables

src/Error404.js

@@ -2,7 +2,6 @@ import React from 'react';
 import NavBar from './NavBar';
 import Footer from "./Footer";
 import { HomeRounded as HomeRoundedIcon } from "@material-ui/icons";
-import LinkButton from "./LinkButton";
 
 export default function PageNotFound() {
 	const navbarItems = [

src/GroupPage.js

@@ -93,7 +93,6 @@ export default withRouter(class GroupPage extends Component {
 						}));
 
 						if (newState.role === "owner") {
-							var counter = 0;
 							const getGroupMembers = () => {
 								return this.state.functions.getGroupMembers({ groupId: this.props.match.params.groupId })
 									.catch((error) => {