[BUGFIX] Better description of [BE][unzip_path]/[BE][diff_path]

The options [BE][unzip_path] and [BE][diff_path] expect different values.
Adjust the descriptions accordingly.

Resolves: #53964
Releases: 6.2, 6.1, 6.0
Change-Id: Id433091f2be77f5c13304619e080a2d1adfb7b0c
Reviewed-on: https://review.typo3.org/25680
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind