Remove unused variables (#3906)

app/javascript/mastodon/features/compose/containers/navigation_container.js

@@ -1,7 +1,7 @@
 import { connect }   from 'react-redux';
 import NavigationBar from '../components/navigation_bar';
 
-const mapStateToProps = (state, props) => {
+const mapStateToProps = state => {
   return {
     account: state.getIn(['accounts', state.getIn(['meta', 'me'])]),
   };