[FIX] account: prevent traceback when creating new bank account

When the `account.journal.bank_statement_source` field is validated at that time
it won't be able to find the `file_import` value in the options of this selection
field as they are dynamically generated and the `file_import` value is generated
in the `account_bank_statement_import` module which is not installed.
So, it will cause Error.

Steps to reproduce :
 1. Install only `account` module
 2. Click on Configuration > Add Bank Account.
 3. Fill up the details. The `Journal` field should be left empty.
 4. Click on Create.

closes odoo/odoo#120923

Sentry: - 4042261837
X-original-commit: eda822ce7c3884350ecfb8bbb10accfe7ff5acf4
Signed-off-by: Brice Bartoletti (bib) <bib@odoo.com>

addons/account/wizard/setup_wizards.py

@@ -139,7 +139,7 @@ class SetupBarBankConfigWizard(models.TransientModel):
                     'type': 'bank',
                     'company_id': company.id,
                     'bank_account_id': record.res_partner_bank_id.id,
-                    'bank_statements_source': 'file_import',
+                    'bank_statements_source': 'undefined',
                 })
             else:
                 selected_journal.bank_account_id = record.res_partner_bank_id.id