Change namespace of DummyClientFace, Signal, Segmenter, SegmentFetcher

refs #3940

Change-Id: Ia3c9b4adcca9ff79a14be705ca9da525914f3dff
diff --git a/tests/test-statistics.cpp b/tests/test-statistics.cpp
index 5aa9855..641d55b 100644
--- a/tests/test-statistics.cpp
+++ b/tests/test-statistics.cpp
@@ -111,7 +111,7 @@
   }
 
 public:
-  ndn::util::DummyClientFace face;
+  ndn::DummyClientFace face;
   ConfParameter conf;
   DummyConfFileProcessor confProcessor;
   Nlsr nlsr;