[FIX] account_financial_report: in XLSX report, display null ending b…

…alance (just like we display null initial balance)

account_financial_report/report/abstract_report_xlsx.py

@@ -496,7 +496,7 @@ def write_ending_balance_from_dict(self, my_object, name, label, report_data):
                         report_data["formats"]["format_header_amount"],
                     )
                 elif cell_type == "amount_currency":
-                    if my_object["currency_id"] and value:
+                    if my_object["currency_id"]:
                         format_amt = self._get_currency_amt_format_dict(
                             my_object, report_data
                         )