limit width of list whose text can grow to silly widths

Change-Id: I982602e829bbf3f2efccfcafae67d22df8daa2e9
(cherry picked from commit 98d311c651347a49f73e8e316be30887e5a99751)
Reviewed-on: https://gerrit.libreoffice.org/12414
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>