Remove delete 0 qty from purchase_usability

[florian-dacosta]

@alexis-via I'd like to remove this method and the button : https://github.com/akretion/odoo-usability/blob/16.0/purchase_usability/models/account_move.py#L11

For now, it does not work in v16. Ok, it is an easy fix but I did not fix it because I'd prefer to remove it and use the OCA modules that avoid the creation of the 0 quantity lines.
I just ported the module OCA/account-invoicing#1602
What do you think ?

[alexis-via]

ok, fine for me if we have an alternative solution

[florian-dacosta]

Thanks, I'll remove the button once the OCA module will be merged!