copy of kiosk let ltsp-build-client fail

Binary package hint: ltsp-server

I want to build a fat ltsp client which starts a java application fullscreen.
So I copied kiosk (and renamed all occurences of 'kiosk' in that file in 'duke').
But then ltsp-build-client fails because it wants to rename a file that has already
been renamed.

In file "/usr/share/ltsp/plugins/ltsp-build-client/Ubuntu/030-kiosk" the following
code is executed in the finalization phase:
    finalization)
        # make sure gdm actually starts
        if [ -e $ROOT/etc/init.d/gdm ]; then
             chroot $ROOT mv /etc/rc2.d/K13gdm /etc/rc2.d/S13gdm
          fi
        ;;

I believe this code should ONLY be executed when the variable KIOSK has
been set. So the code should be:
    finalization)
        if [ -n "$KIOSK" ]; then
            # make sure gdm actually starts
            if [ -e $ROOT/etc/init.d/gdm ]; then
                chroot $ROOT mv /etc/rc2.d/K13gdm /etc/rc2.d/S13gdm
            fi
        fi
        ;;