For certain reasons, I want to allow BoM-component to appear in the Bom list with a quantity set to zero. I have edited the mrp.py line 235-236 to skip the qty check and deleted the mrp_bom_qty_zero constraint from the Model Constraint panel in the browser client. Still, when trying to import data where qty=0 appears, I get the error "new row for relation "mrp_bom" violates check constraint "mrp_bom_bom_qty_zero" ". 

Where can I completely disable this constraint?

Best,