Update reply to DHCP-Ack

[Leo Combes]

Works fine with this:

if(ok){
	update request {
		DHCP-Message-Type := DHCP-Ack
	}
	deselabs_dhcp_cpes.post-auth
}

See that I use "update request" instead of "update reply".
I don't know if is correct this way, but works.