We need to update the transformation primitive wrapping the chart when
the grid offset is changed.

Change-Id: I42179fdc7cc806c5757a125881f08279767ccbcc
Reviewed-on: https://gerrit.libreoffice.org/36255Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan Holesovsky <kendy@collabora.com>