[FIX] pos_restaurant: Use order printers with HTTPS

The protocol and port to use when printing orders were hardcoded. This
resulted in errors when using the POS in HTTPS as the browser blocked
non-HTTPS requests on the page.

closes odoo/odoo#64814

Taskid: 2413240
Signed-off-by: Quentin Lejeune (qle) <qle@odoo.com>