[BUGFIX] Cannot download manuals

Since the UX renaming, it is not possible anymore to download
manuals from docs.typo3.org.

Fixes: #55126
Releases: 6.2
Change-Id: Iee5d8fda83dc9ad6b9b2ecfa668f7587a99170ff
Reviewed-on: https://review.typo3.org/26917
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters