[FIX] account_analytic_default: invoice, avoid account overwrite

Due to the following revision:
bdf630f9b89a3d47c3826dac6fe9a04e6aa701d5

When creating an invoice from a purchase order with an
analytic account set, the analytic account was no longer
copied on the invoice, as the analytic account that was added
thanks to
https://github.com/odoo/odoo/blob/9.0/addons/purchase/invoice.py#L53
was overwritten with `False` as `rec` was False
or if `rec` was True, it was overwritten with the analytic account
of `rec`.

opw-697702

0 files changed, 0 insertions, 0 deletions