Fem: [skip ci] handle exception in Fem Constraint in case referenced shape element doesn't exist
Fem: [skip ci] handle exception in Fem Constraint in case referenced shape element doesn't exist

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