unblock v6 network segment but isolate local node address

As $addr6 contains a /64 all outgoing v6 traffic to the network was blocked. Now we cut off all netmask values and replace them with /128 for the v6 local node address.

files/etc/uci-defaults/50_freifunk-setup

@@ -142,8 +142,9 @@ initial_local_node_setup()
 	ebtables -A OUTPUT --logical-out br-freifunk -o bat0 -p IPv4 --ip-source $addr4 -j DROP
 
 	# Isolate local-node IPv6 address
-	ebtables -A FORWARD --logical-out br-freifunk -o bat0 -p IPv6 --ip6-dst $addr6 -j DROP
-	ebtables -A OUTPUT --logical-out br-freifunk -o bat0 -p IPv6 --ip6-dst $addr6 -j DROP
+	# WARNING - wrong setting here can cause Autoupdater to be blocked - WARNING
+	ebtables -A FORWARD --logical-out br-freifunk -o bat0 -p IPv6 --ip6-dst ${addr6%/*}/128 -j DROP
+	ebtables -A FORWARD --logical-out br-freifunk -o bat0 -p IPv6 --ip6-dst ${addr6%/*}/128 -j DROP
 	EOF
 }