Avoid using deprecated ndn-cxx functions

Change-Id: I51e0abcb7454e31efbcc779a17d2c490802108ec
diff --git a/src/util/util.cpp b/src/util/util.cpp
index 7d350a5..8466733 100644
--- a/src/util/util.cpp
+++ b/src/util/util.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019, Regents of the University of California.
+ * Copyright (c) 2014-2020, Regents of the University of California.
  *
  * This file is part of NDNS (Named Data Networking Domain Name Service).
  * See AUTHORS.md for complete list of NDNS authors and contributors.
@@ -64,8 +64,11 @@
     bufferSource(block.wire(), block.size()) >> base64Encode() >> streamSink(os);
   }
   else {
-    os << "Name: " << data.getName().toUri() << std::endl;
-    os << "KeyLocator: " << data.getSignature().getKeyLocator().getName().toUri() << std::endl;
+    os << "Name: " << data.getName() << std::endl;
+    auto kl = data.getKeyLocator();
+    if (kl) {
+      os << "KeyLocator: " << kl->getName() << std::endl;
+    }
     bufferSource(block.wire(), block.size()) >> base64Encode() >> streamSink(os);
     os << std::endl;
   }