Auto-logout dialog and admin menu are shown when logged out

Steps to reproduce

• Configure auto-logout to be On and set for 50s
• View the /admin/content page
• Wait for 50s and don't interact with the window
• Alert pops up as expected. Allow it to disappear without interacting with it
• After 5s the url changes to /admin/undefined. The admin toolbar remains shown and the page content says "The requested page could not be found."
• Wait for 50s and don't interact with the window
• Alert pops up again
• This time the url changes to /undefined and the admin menu disappears

Proposed resolution

• Only show the popup once.
• Ensure that the admin toolbar is not displayed when the user is logged out.