Fix 404 console error when user is signed out

app/views/errors/_footer.html.haml

@@ -4,8 +4,8 @@
       = link_to s_('Nav|Home'), root_path
     %li
       - if current_user
-        = link_to s_('Nav|Sign out and sign in with a different account'), '#', id: 'sign_out_link'
-        %form{ action: destroy_user_session_path, method: :post, id: 'sign_out_form' }
+        = link_to s_('Nav|Sign out and sign in with a different account'), '#', class: 'js-sign-out-link'
+        %form.js-sign-out-form{ action: destroy_user_session_path, method: :post }
       - else
         = link_to s_('Nav|Sign In / Register'), new_session_path(:user, redirect_to_referer: 'yes')
     %li

app/views/layouts/errors.html.haml

@@ -22,8 +22,8 @@
           }
 
           // We do not have rails_ujs here, so we're manually making a link trigger a form submit.
-          document.getElementById('sign_out_link').addEventListener('click', function(e) {
+          document.querySelector('.js-sign-out-link')?.addEventListener('click', (e) => {
             e.preventDefault();
-            document.getElementById('sign_out_form').submit();
+            document.querySelector('.js-sign-out-form')?.submit();
           });
         }());