paymend_mode category is required for payment simulation.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32019 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/PropertySheet/Simulation.py

@@ -65,5 +65,5 @@ class Simulation:
             'mode'        : 'w' },
   )
 
-  _categories = ('order', 'delivery', 'delivery_mode', 'incoterm', 'solver')
+  _categories = ('order', 'delivery', 'delivery_mode', 'incoterm', 'payment_mode', 'solver')