This reverts commit 343af46f (ODT
filter: make sure we have a layout before export, 2017-11-29) as it
causes a performance problem with large documents (see bugreport).

I added it initially for the EPUB export, but there this is no longer
needed as commit 3ed8466b (EPUB export,
fixed layout: switch to a metafile-based approach, 2017-12-01) switched
to the better metafile-based approach.

Change-Id: Ie404e23db77b8ded1d29f42b6279a3cd06a574b5
Reviewed-on: https://gerrit.libreoffice.org/62924
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>