If user changed quantity of products to amount that would create free cart, without refreshing the page, they were still able to use express checkout which was causing an error. If user has free cart now, it will make express checkout button dissapear. task-3568644 closes odoo/odoo#160386 X-original-commit: 0b47abaa6d682fb5c243d1b36dbed263343ce586 Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com> Signed-off-by: anko-odoo <anko@odoo.com>