FEM: Py3 fix, do not open file in binary mode if writing strings
FEM: Py3 fix, do not open file in binary mode if writing strings

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