Web Sudo: "Drop access" link does not work when language is set to german

When Confluence's language is set to german, then the Web Sudo "Drop Access" link in the title bar points to a non-existing URL.

Steps to reproduce:

1. Set language to german.
2. Make sure that web sudo mode is on (e. g. by going to the admin area).
3. Leave the admin area and go to a normal page inside a space (in this example the space key is "TEST").
4. Click the "drop access" link in the title bar. In german the text is "Zugriff trennen".
5. The link points to this url: http://localhost:8081/display/TEST/drop-passive
6. When the user clicks the link, then the "Page not found" screen appears.