Arch: Dice3DS/dom3ds.py LGTM fix
Arch: Dice3DS/dom3ds.py LGTM fix

Following recommendations from https://lgtm.com/rules/6770081/
Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master