Updated core

Project: help  9f7edddfe613a3e61a1160028c853d9fc569876a

Make xml-lang optional in help DTD

Change DTD to make xml-lang optional, as requested by patch
https://gerrit.libreoffice.org/#/c/32296/

Change-Id: I5ef02dddb8486b75e16f3b141aa792b1dfb43f86
Reviewed-on: https://gerrit.libreoffice.org/38465Reviewed-by: Olivier Hallot <olivier.hallot@edx.srv.br>
Tested-by: Olivier Hallot <olivier.hallot@edx.srv.br>
Reviewed-by: Jan Holesovsky <kendy@collabora.com>

helpcontent2 @ 9f7edddf

-Subproject commit ae4b238aec8977510b63b5a30c71e0aa933c279a
+Subproject commit 9f7edddfe613a3e61a1160028c853d9fc569876a