destination_url cookie is used to redirect the user to the a private
page after they have logged in. After deleting own account, a user's
pages would be refreshed which would set the destination_url, cookie
that can cause a redirect to an invalid page after logging in again.
Reproduction steps:
1. User is at `/u/:username/preferences/account` and deletes account by
requesting DELETE `/u/:username.json`.
2. User is being destroyed and a MessageBus message (`file-change`,
`['refresh']`) is published.
3. User receives response to DELETE request, but page may be or not
refreshed. Anyway, since they can no longer see the preferences page,
they are redirected to `/login` and `destination_url` cookie is set,
that will redirect on next login (but to the previous preferences page).