[FIX] sale_three_discount: add products with discount
[FIX] sale_three_discount: add products with discount

closes ingadhoc/sale#560

X-original-commit: 102406a81a77d7e061f546f5521a45c6bea95881
Signed-off-by: Nicolas Mac Rouillon <8d34fe7b7c65100e706828a8c0d03426900ffb59@adhoc.com.ar>

ingadhoc/sale,ingadhoc/sale,ingadhoc/sale,ingadhoc/sale