Resolves: fdo#65823 crash on negative position in redlined word

there is possibly something deeper wrong here I think after all, see
946ea643185af680508a0333f63c086ed3f454a3 Resolves: fdo#84649 as well but for
now silence this and I can investigate further later

Change-Id: I1323584d1f71c14634d56ad4e4a705496b1bd1c0
(cherry picked from commit d7418f8831acdff907d404c1701870b00e974df6)
Reviewed-on: https://gerrit.libreoffice.org/11884
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>