[FIX] account: no account in manual move creation
[FIX] account: no account in manual move creation

- Activate multi-currency
- Create an Journal Entry manually
- Create a line
  Do not fill Account
  Fill in Amount Currency
  Fill in Currency

A traceback occurs because `line.company_currency_id`.

An extra condition `and line.company_currency_id` is not sufficient to
have the onchange working properly. Indeed, the related field
`company_currency_id` goes through another related field (`company_id`),
leading to an empty value in some cases.

opw-1904854

closes odoo/odoo#28389
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo