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

Change-Id: I4c8d2e90bd0279cc6221ec58790de19d656f4ca3
diff --git a/tests/face/ethernet.cpp b/tests/face/ethernet.cpp
index 706a697..d27fda4 100644
--- a/tests/face/ethernet.cpp
+++ b/tests/face/ethernet.cpp
@@ -118,7 +118,7 @@
   BOOST_CHECK(!face->isOnDemand());
   BOOST_CHECK_EQUAL(face->isLocal(), false);
   BOOST_CHECK_EQUAL(face->getRemoteUri().toString(),
-                    "ether://" + ethernet::getDefaultMulticastAddress().toString(':'));
+                    "ether://" + ethernet::getDefaultMulticastAddress().toString());
   BOOST_CHECK_EQUAL(face->getLocalUri().toString(),
                     "dev://" + m_interfaces.front()->name);