[DOCS] Fix wrong value in rst file of #89603

The key should be 4 instead of 5 (index starts at 0).

Resolves: #90982
Releases: master
Change-Id: Iee33a74d8f569082aa495025892131acc0a392a7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64101


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Christian Eßl <indy.essl@gmail.com>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Christian Eßl <indy.essl@gmail.com>