erp5testnode: Add the protocol name to nat-rule-port
Now the nat-rule-port always has the protocol name, see here: https://lab.nexedi.com/nexedi/slapos/blob/9a886c4b0c6dd229564292eaa0ef2604fa857aea/software/kvm/instance-kvm.cfg.jinja2#L843
Now the nat-rule-port always has the protocol name, see here: https://lab.nexedi.com/nexedi/slapos/blob/9a886c4b0c6dd229564292eaa0ef2604fa857aea/software/kvm/instance-kvm.cfg.jinja2#L843