[BUGFIX] Fix missing label in Site Config

The "Language" header used in in the table listing was never shown,
as it was missing in the language file.

Resolves: #90475
Releases: master, 9.5
Change-Id: Ic14e1b808bf10da6e1096829451945ece7d6943c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63358


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>