Do the changes in 7c0f6b9d
only if the destination is not an undo document.

Also removes the below unnecessary change in that commit.

if ( IsNoteCaption( pOldObject ) )
{
    pOldObject = aIter.Next();
    continue;
}

Change-Id: Ib18324ed16e91dbd932d449858a489dc09c53713
Reviewed-on: https://gerrit.libreoffice.org/56287
Tested-by: Jenkins
Reviewed-by: Eike Rathke <erack@redhat.com>