respondd: use vxlan interface

roles/install_mesh-announce/templates/respondd.service.j2

@@ -3,7 +3,7 @@ Description=Respondd
 After=network.target
 
 [Service]
-ExecStart=/opt/mesh-announce/respondd.py -d /opt/mesh-announce/providers {% for site in sites %}-i bat{{ site.name }} -i vpn{{ site.name }} -b bat{{ site.name }} {% endfor %}
+ExecStart=/opt/mesh-announce/respondd.py -d /opt/mesh-announce/providers {% for site in sites %}-i bat{{ site.name }} -i vx{{ site.name }} -b bat{{ site.name }} {% endfor %}
 
 Restart=always
 Environment=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin