datev_export_xml: bp_account_no seems wrong

[derfl0]

Module

datev_export_xml

Describe the bug

The xml export tries to add the field bp_account_no to the export. The validator states that this field is only of length 4 but should be at least length 5. The code tries to put in account.code which is the number according to skr03/skr04.

As far as I understand https://apps.datev.de/help-center/documents/1035732 bp_account_no should be the bank account number of the partner and is optional. I tried to use a IBAN in this field but it looks like it needs an integer primary key.

As the field is purely optional I'd suggest just removing it

To Reproduce

Affected versions: 16.0

Steps to reproduce the behavior:

1. Create export
2. Get error

Expected behavior
Export without errors