build: align minimum build dependencies with ndn-cxx

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

Also update waf to version 2.0.23

Change-Id: Id4eb36b068569636d6077b90dd784f9c3c451e9a
diff --git a/src/ndn-traffic-server.cpp b/src/ndn-traffic-server.cpp
index 25ace67..b85556c 100644
--- a/src/ndn-traffic-server.cpp
+++ b/src/ndn-traffic-server.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019, Arizona Board of Regents.
+ * Copyright (c) 2014-2022, Arizona Board of Regents.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -271,7 +271,7 @@
         content = getRandomByteString(*pattern.m_contentLength);
       if (!pattern.m_content.empty())
         content = pattern.m_content;
-      data.setContent(reinterpret_cast<const uint8_t*>(content.data()), content.length());
+      data.setContent(makeStringBlock(tlv::Content, content));
 
       m_keyChain.sign(data, pattern.m_signingInfo);