Describe the bug
After updating to Bookstack 21.05.1 with a SAML login, the login does not work anymore, showing
Undefined variable: currentUser (View: /var/www/bookstack/resources/views/partials/sort.blade.php)
Steps To Reproduce
Steps to reproduce the behavior:
- Update to Bookstackt 21.05.1
- Login via SAML provider (Keycloak 12)
Expected behavior
Login should work
Screenshots

Your Configuration (please complete the following information):
- Exact BookStack Version (Found in settings): 21.05.1
- PHP Version: 7.4.20
- Hosting Method (Nginx/Apache/Docker): Docker
Additional context
Keycloak SAML Login