l10n_it_intrastat_statement: progressive_to_modify_id is not used

[eLBati]

l10n_it_intrastat_statement

To Reproduce

Affected versions:

• [ ] 14.0
• [x] 16.0 #4186

Steps to reproduce the behavior:

• Create a intrastat statement with Purchases Services adjustment - section 4
• Export file Dogana

File check fails with "Il campo Progressivo Sez. III deve essere maggiore di zero"