[FIX] account: initial balance
[FIX] account: initial balance

- Create manually an account move
- Add a line with a credit != 0
- Click on "Add a line" => crash

`line_ids` does not contain the credit since it was not filled in.

opw-782980

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo