[FIX] account_voucher: Sign Amount currency correctly
[FIX] account_voucher: Sign Amount currency correctly

Before this patch Amount currency was always +ve and doesn't care about about Debit/Credit values.
See _check_currency_amount constrains.
Fixes: #35403

closes odoo/odoo#35422

Signed-off-by: Cedric Snauwaert (csn) <0913683871cd6a284d24f0b73c0d0c7b5d961c19@openerp.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo