Avoid JS error when logged out

Author: silverwind

web_src/js/features/repo-issue-list.js

@@ -40,7 +40,7 @@ function initRepoIssueListCheckboxes() {
     el.addEventListener('change', syncIssueSelectionState);
   }
 
-  issueSelectAll.addEventListener('change', () => {
+  issueSelectAll?.addEventListener('change', () => {
     for (const el of issueCheckboxes) {
       el.checked = issueSelectAll.checked;
     }