Resolves: fdo#79129 Crash in oox::drawingml::LayoutNode::setupShape

Change-Id: I0bafd2c43d29806eea0ff0cb165e67aece53488f
Reviewed-on: https://gerrit.libreoffice.org/11726
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>