[purchase] Purchase orders based on incoming shipment should be done when invoices are paid, not just validated

Hello,

I have fixed the issue : Purchase orders based on incoming shipment should be done when invoices are paid, not just validated.

More details:
https://www.odoo.com/web?#id=7359&view_type=form&model=project.task&menu_id=3942&action=327
https://pad.odoo.com/p/r.PrydjG8E6GUHEGah

Thanks & Regards,
Jaydeep Barot (jar)