[FIX] point_of_sale: get rid of paymentlines with an amount of 0
[FIX] point_of_sale: get rid of paymentlines with an amount of 0

Since c04065abd8f62c9a211c8fa824f5eecf68e61b73 (introduction of
accounting v9) bank statement lines can not have an amount of zero
anymore. So when we validate an order in the POS client we need to get
rid of paymentlines with an amount of zero.

ygol/odoo,stephen144/odoo,syci/OCB,syci/OCB,dfang/odoo,laslabs/odoo,hip-odoo/odoo,Elico-Corp/odoo_OCB,sysadminmatmoz/OCB,laslabs/odoo,dfang/odoo,ygol/odoo,syci/OCB,storm-computers/odoo,hip-odoo/odoo,sysadminmatmoz/OCB,optima-ict/odoo,storm-computers/odoo,syci/OCB,ygol/odoo,storm-computers/odoo,sysadminmatmoz/OCB,storm-computers/odoo,microcom/odoo,dfang/odoo,stephen144/odoo,storm-computers/odoo,stephen144/odoo,microcom/odoo,bplancher/odoo,sysadminmatmoz/OCB,optima-ict/odoo,microcom/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,optima-ict/odoo,Elico-Corp/odoo_OCB,bplancher/odoo,bplancher/odoo,sysadminmatmoz/OCB,laslabs/odoo,bplancher/odoo,laslabs/odoo,dfang/odoo,bplancher/odoo,microcom/odoo,dfang/odoo,Elico-Corp/odoo_OCB,syci/OCB,syci/OCB,sysadminmatmoz/OCB,stephen144/odoo,ygol/odoo,hip-odoo/odoo,bplancher/odoo,Elico-Corp/odoo_OCB,ygol/odoo,sysadminmatmoz/OCB,storm-computers/odoo,optima-ict/odoo,optima-ict/odoo,stephen144/odoo,Elico-Corp/odoo_OCB,ygol/odoo,hip-odoo/odoo,optima-ict/odoo,microcom/odoo,laslabs/odoo,dfang/odoo,microcom/odoo,hip-odoo/odoo,laslabs/odoo,ygol/odoo,hip-odoo/odoo