[FIX] website_sale: do not use undefined variable
[FIX] website_sale: do not use undefined variable

Error introduced by previous forward-port

ygol/odoo,ygol/odoo,hip-odoo/odoo,hip-odoo/odoo,ygol/odoo,hip-odoo/odoo,ygol/odoo,ygol/odoo,hip-odoo/odoo,hip-odoo/odoo,dfang/odoo,ygol/odoo,dfang/odoo,hip-odoo/odoo,dfang/odoo,dfang/odoo,ygol/odoo,dfang/odoo,dfang/odoo