Switch order of arguments to implode().

Resolves: #83158
Releases: master, 8.7
Change-Id: I15ff9827418e9d24fefae5f3fa8852a37f5363d0
Reviewed-on: https://review.typo3.org/54881


Reviewed-by: Benjamin Kott <benjamin.kott@outlook.com>
Tested-by: Benjamin Kott <benjamin.kott@outlook.com>