tests: avoid deprecated boost headers

Change-Id: I05aa8d5fd22843415db09478f7b53f1810b38db3
diff --git a/tests/unit/util/indented-stream.t.cpp b/tests/unit/util/indented-stream.t.cpp
index b3edaf8..f07990a 100644
--- a/tests/unit/util/indented-stream.t.cpp
+++ b/tests/unit/util/indented-stream.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2019 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -23,7 +23,11 @@
 
 #include "tests/boost-test.hpp"
 
+#if BOOST_VERSION >= 105900
+#include <boost/test/tools/output_test_stream.hpp>
+#else
 #include <boost/test/output_test_stream.hpp>
+#endif
 
 namespace ndn {
 namespace util {