Before this commit when you unlink a sale.order.line the field carrier_id of sale.order is set False for each delivery line. This commit prevent also serialisation failure on ecommerce. closes odoo/odoo#143533 X-original-commit: c9fe8d113deb8103ad531d999f75f74c5475f46e Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com> Co-authored-by: vava-odoo <112173839+vava-odoo@users.noreply.github.com>