face: change default separator for ethernet::Address::toString() to ':'

Change-Id: I4c8d2e90bd0279cc6221ec58790de19d656f4ca3
diff --git a/daemon/face/ethernet-face.cpp b/daemon/face/ethernet-face.cpp
index 5f12103..02cc041 100644
--- a/daemon/face/ethernet-face.cpp
+++ b/daemon/face/ethernet-face.cpp
@@ -70,8 +70,8 @@
   ::snprintf(filter, sizeof(filter),
              "(ether proto 0x%x) && (ether dst %s) && (not ether src %s)",
              ETHERTYPE_NDN,
-             m_destAddress.toString(':').c_str(),
-             m_srcAddress.toString(':').c_str());
+             m_destAddress.toString().c_str(),
+             m_srcAddress.toString().c_str());
   setPacketFilter(filter);
 
   m_socket->async_read_some(boost::asio::null_buffers(),