Fix firewall to take into account wireguard (wg) interfaces

roles/common/templates/ferm/ferm.conf.j2

@@ -13,7 +13,7 @@
 @def $NETDEV = `ip route list | sed -r -n 's/^default\s+via\s+.*\s+dev\s+([a-z0-9]+).*$/\1/p'`;
 {% endif %}
 # Detecting list of bridge network interfaces
-@def $BRIDGES = `ip link show up | sed -r -n 's/^[0-9]:\s+((xen|)br[^:]+):\s+.*$/\1/p' | xargs`;
+@def $BRIDGES = `ip link show up | sed -r -n 's/^[0-9]+:\s+((xenbr|br|wg)[^:]+):\s+.*$/\1/p' | xargs`;
 
 # Default policies
 domain (ip ip6) {