also fix bug in ScDocShell::DBAreaDeleted which has been there ever
since it's initial commit in
    commit 9ae5a91f
    Author: Jens-Heiner Rechtien <hr@openoffice.org>
    Date:   Mon Sep 18 16:07:07 2000 +0000
    initial import

Change-Id: Ifc8d6dec4843c668404fdf1ca1a9e521f73132d5
Reviewed-on: https://gerrit.libreoffice.org/37459Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>