* Fix Sale and PurchaseOrder_view/listbox_quantity_unit  to show empty drop-down list if the line does not have any resource. This fix makes Delivery and Line  consistence of quantity_unit displaying.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@30465 20353a03-c40f-0410-a6d1-a30d3c3de9de