This used to work in the past only because the left indent was also
imported as a direct paragraph formatting, but that is not the case
since left margin of lists is deduplicated during import after commit
c9dee880 (tdf#104016 RTF import:
deduplicate before text indent from numbering, 2017-12-05).

Change-Id: I1c9be30700c51ef97fb274e8781d6008db3121d8
Reviewed-on: https://gerrit.libreoffice.org/48855Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>