Revert "[BUGFIX] setRespectSysLanguage(FALSE) doesn't prevent language overlay"

This reverts commit 58c9017fbdeb9108c15e80de4fb726c1f9273b8b

The patch introduces a regression. We have no easy fix for it, so the patch gets reverted. Sorry for now, we come back to the problem.

Change-Id: I8b608146a72cd48988c77ecf1036ac85074e03b0
Reviewed-on: https://review.typo3.org/22671
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring