[FIX][l10n_it_account] Fix base amount tax partially undeductible

Author: alessandrocamilli

l10n_it_account/models/account_tax.py

@@ -187,6 +187,7 @@ def _compute_totals_tax(self, data):
             for child in tax.children_tax_ids:
                 child_balance = child.balance
                 tax_balance += child_balance
+                base_balance += child.base_balance
                 account_ids = (
                     child.mapped("invoice_repartition_line_ids.account_id")
                     | child.mapped("refund_repartition_line_ids.account_id")