fdo#80009: xmloff: ignore excessive fo:clip values

These cause problems in drawinglayer, and nobody needs a 5km clip.

Change-Id: Ic485250413194adbcd0ccf855f12e89e532d7120
(cherry picked from commit 924a28a7b1dc2f89e6940630057557f5f03494df)
Reviewed-on: https://gerrit.libreoffice.org/9947
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>