SW_DRAWLAYER had the same value as SC_DRAWLAYER, so I merged it into the
ScOrSwDraw enum constant

Change-Id: I5c45d378c00364d11cc960c9e48a6e3f10928724
Reviewed-on: https://gerrit.libreoffice.org/31037Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>