Fix close keyboard shortcuts dialog using the keyboard shortcut

app/assets/javascripts/shortcuts.js

@@ -85,6 +85,7 @@ export default class Shortcuts {
 
     if ($modal.length) {
       $modal.modal('toggle');
+      return null;
     }
 
     return axios.get(gon.shortcuts_path, {

changelogs/unreleased/fix-shortcut-close-screen-with-key.yml

+---
+title: Fix close keyboard shortcuts dialog using the keyboard shortcut
+merge_request: 18783
+author: Lars Greiss
+type: fixed