build: align minimum build dependencies with ndn-cxx

 * boost 1.65.1
 * gcc 7.4
 * clang 6.0
 * Xcode 10.0 (11.3 or later recommended)

Change-Id: I5e41f2a70d6c510dcb889a083a51504121b4627d
diff --git a/tests/tools/nfdc/help.t.cpp b/tests/tools/nfdc/help.t.cpp
index c5d5012..6f5392c 100644
--- a/tests/tools/nfdc/help.t.cpp
+++ b/tests/tools/nfdc/help.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -27,11 +27,7 @@
 
 #include "tests/test-common.hpp"
 
-#if BOOST_VERSION >= 105900
 #include <boost/test/tools/output_test_stream.hpp>
-#else
-#include <boost/test/output_test_stream.hpp>
-#endif
 
 namespace nfd {
 namespace tools {