Revert "Add support for characterset used by mb_strtoupper"

This reverts commit 24b8dd93b6b080f01d9fcd4b9fc1dd0e7bdc67af.
Revert "Revert "Add support for characterset used by mb_strtoupper""

This reverts commit 4cd3861e490b82f739adecb70afd797c385337ff.
adjusted the indentation