[BUGFIX] Fix localization guard for "pages_language_overlay"

Resolves: #79859
Related: #78191
Releases: master, 7.6
Change-Id: Ia2a3ed9b1a793c1be554f73fa99362e3015313df
Reviewed-on: https://review.typo3.org/51720


Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Thomas Hohn <thomas@hohn.dk>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>