fdo#46410 fix FindRange

Change-Id: I7aada76bc2e8e767f36016eee5e57267b3718b13
Reviewed-on: https://gerrit.libreoffice.org/6657
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>