fixup! accounting: Optimize initial balance calculation

we should not call getInventoryList if there is no account_type_to_group_by_mirror_section_previous_period

bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/AccountModule_getAccountListForTrialBalance.xml

@@ -501,7 +501,8 @@ for node in getInventoryList(\n
 \n
 # payable / receivable accounts {{{\n
 # initial balance\n
-for node in getInventoryList(\n
+if account_type_to_group_by_mirror_section_previous_period:\n
+  for node in getInventoryList(\n
                   node_category_strict_membership=account_type_to_group_by_mirror_section_previous_period,\n
                   group_by_mirror_section=1,\n
                   group_by_node=1,\n
@@ -524,7 +525,8 @@ for node in getInventoryList(\n
 \n
 found_balance=False\n
 # Balance Transactions\n
-for node in getInventoryList(\n
+if account_type_to_group_by_mirror_section_previous_period:\n
+  for node in getInventoryList(\n
                   node_category_strict_membership=account_type_to_group_by_mirror_section_previous_period,\n
                   group_by_mirror_section=1,\n
                   group_by_node=1,\n
@@ -711,7 +713,7 @@ for key, data in line_per_account.items():\n
   closing_balance = final_debit_balance - final_credit_balance\n
   total_final_balance_if_debit += round(max(closing_balance, 0), precision)\n
   total_final_balance_if_credit += round(max(-closing_balance, 0) or 0, precision)\n
-  \n
+\n
   line = Object(uid=\'new_\',\n
                 node_id=node_id,\n
                 node_title=node_title,\n