[BUGFIX] CSV-Download not working in IE and HTTPS backend
When using a HTTPS backend the download of CSV is not working in Internet Explorer browser versions lower then 9. Add the needed header to fix this problem. Change-Id: Iefa63fb37d57491fb73bfd504b6caed5b76c8cac Resolves: #16491 Releases: 6.2, 6.1, 6.0, 4.7, 4.5 Reviewed-on: https://review.typo3.org/20902 Reviewed-by: Markus Klein Tested-by: Markus Klein Reviewed-by: Christian Kuhn Tested-by: Christian Kuhn