ocserv: use numeric ID instead of arbitrary USERNAME for nft chain name

Putting a @ in a name is a bad.

roles/ocserv/files/ocserv-script

@@ -3,10 +3,10 @@
 set -x
 
 [ -n "$DEVICE" ] || exit 1
-[ -n "$USERNAME" ] || exit 2
+[ -n "$ID" ] || exit 2
 [ -n "$IP_REMOTE" ] || exit 3
 
-chain="inet ocserv client-${USERNAME}"
+chain="inet ocserv client-${ID}"
 remote_ip="${IP_REMOTE%/*}"
 
 case "${REASON}" in

roles/ocserv/templates/ocserv.conf.j2

@@ -1,5 +1,6 @@
 listen-host = {{ dns_name }}
 tcp-port = 443
+udp-port = 443
 server-cert = /etc/letsencrypt/live/{{ dns_name }}/fullchain.pem
 server-key = /etc/letsencrypt/live/{{ dns_name }}/privkey.pem