[FIX] account_voucher: fix onchange price_unit
[FIX] account_voucher: fix onchange price_unit

before this commit, on a sales voucher, the unit price on the lines wouldn't take the value we wrote in the field
It is now the case

OPW 765993

ygol/odoo,ygol/odoo,Elico-Corp/odoo_OCB,Elico-Corp/odoo_OCB,ygol/odoo,Elico-Corp/odoo_OCB,ygol/odoo,ygol/odoo,ygol/odoo,Elico-Corp/odoo_OCB,Elico-Corp/odoo_OCB,Elico-Corp/odoo_OCB,ygol/odoo