Avoid loading rails-ujs twice on vanilla flavour

app/javascript/core/common.js

@@ -1,8 +1,5 @@
 //  This file will be loaded on all pages, regardless of theme.
 
-import { start } from 'rails-ujs';
 import 'font-awesome/css/font-awesome.css';
 
 require.context('../images/', true);
-
-start();

app/javascript/flavours/glitch/packs/common.js

@@ -1,3 +1,7 @@
+import { start } from 'rails-ujs';
+
+start();
+
 import 'flavours/glitch/styles/index.scss';
 
 //  This ensures that webpack compiles our images.