testAdvancedInvoicing: remove noop/broken statement

Any use of erp5_sql_transactionless_connection must end with an explicit SQL
commit, otherwise it does nothing and it may even leave SQL locks.

Contrary to InnoDB, TokuDB locks on such statement. test_InvoiceViewAsODT
is the only test that does not use erp5_sql_transactionless_connection
(other tests do via IdTool), breaking the next test
(test_PackingListEditAndInvoiceRule) with "Lock wait timeout exceeded" error.

One would except that the tests use the same instance of
erp5_sql_transactionless_connection, and in this case it would not fail, but
for bad reasons, tests alternate between 2 different ZODB Connection instances.

product/ERP5/tests/testAdvancedInvoicing.py

@@ -418,10 +418,6 @@ class TestAdvancedSaleInvoice(TestAdvancedInvoice):
           'portal_deliveries/advanced_purchase_invoice_transaction_builder',
           'portal_deliveries/advanced_sale_invoice_transaction_builder',
           ])
-    # This is quite ugly, we should use late import/export functions of generators
-    self.portal.erp5_sql_transactionless_connection.manage_test(
-     "delete from portal_ids where \
-       id_group='Accounting_Transaction_Module-Sale_Invoice_Transaction'")
     self.commit()
 
   def stepCheckInvoicesAndTransactionsConsistency(self, sequence=None, sequence_list=None,