tests: fix UDP multicast transport tests with IPv6

A valid scope id is always required on the multicast address

Change-Id: Ic676fcde0ee50daf75eb38c137e3cb917f43699f
diff --git a/daemon/face/udp-factory.hpp b/daemon/face/udp-factory.hpp
index 475621d..f0cd686 100644
--- a/daemon/face/udp-factory.hpp
+++ b/daemon/face/udp-factory.hpp
@@ -90,7 +90,7 @@
    * \throw UdpFactory::Error
    */
   shared_ptr<Face>
-  createMulticastFace(const shared_ptr<const ndn::net::NetworkInterface>& netif,
+  createMulticastFace(const ndn::net::NetworkInterface& netif,
                       const boost::asio::ip::address& localAddress,
                       const udp::Endpoint& multicastEndpoint);