proxyvm: allow for user defined hooks after iptables restore

proxyvm/bin/qubes_firewall

@@ -35,4 +35,7 @@ while true; do
 		# If OK save it for later
 		/sbin/service iptables save >/dev/null
 	fi
+
+	# Check if user didn't define some custom rules to be applied as well...
+	[ -x /rw/config/qubes_firewall_user_script ] && /rw/config/qubes_firewall_user_script
 done