openvpn config: fix proto in template

config/roles/openvpn/templates/udp.conf.j2

@@ -12,7 +12,6 @@ duplicate-cn
 keepalive 10 30
 mute-replay-warnings
 mute 5
-proto udp6
 push "redirect-gateway def1 ipv6"
 push "dhcp-option DNS {{ openvpn_network | ipaddr('1') | ipaddr('address') }}"
 {% if openvpn_network6 is defined and openvpn_network6|length %}
@@ -21,7 +20,7 @@ server-ipv6 {{ openvpn_network6 }}
 push "route-ipv6 2000::/3"
 push "dhcp-option DNS {{ openvpn_network6 }}"
 {% else %}
-proto tcp
+proto udp
 push "ifconfig-ipv6 fd15:53b6:dead::2/64 fd15:53b6:dead::1"
 block-ipv6
 {% endif %}