build: require boost >= 1.71.0

Refs: #5276
Change-Id: Ie428541639dcf1113acfb9e9d0a80f9be87d6cd3
diff --git a/tools/ndn-autoconfig/ndn-fch-discovery.cpp b/tools/ndn-autoconfig/ndn-fch-discovery.cpp
index 52521e7..0e5c6b0 100644
--- a/tools/ndn-autoconfig/ndn-fch-discovery.cpp
+++ b/tools/ndn-autoconfig/ndn-fch-discovery.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  Regents of the University of California,
+ * Copyright (c) 2014-2023,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -140,11 +140,7 @@
 {
   try {
     boost::asio::ip::tcp::iostream requestStream;
-#if BOOST_VERSION >= 106700
     requestStream.expires_after(std::chrono::seconds(3));
-#else
-    requestStream.expires_from_now(boost::posix_time::seconds(3));
-#endif // BOOST_VERSION >= 106700
 
     Url url(m_url);
     if (!url.isValid()) {
diff --git a/tools/ndn-autoconfig/procedure.hpp b/tools/ndn-autoconfig/procedure.hpp
index 3f1f630..d9513ed 100644
--- a/tools/ndn-autoconfig/procedure.hpp
+++ b/tools/ndn-autoconfig/procedure.hpp
@@ -57,7 +57,7 @@
   void
   runOnce();
 
-  boost::asio::io_service&
+  boost::asio::io_context&
   getIoService()
   {
     return m_face.getIoService();
diff --git a/tools/wscript b/tools/wscript
index 5a9c396..23cdf0a 100644
--- a/tools/wscript
+++ b/tools/wscript
@@ -63,7 +63,7 @@
             bld.objects(target=srcObjects,
                         source=srcFiles,
                         features='pch',
-                        headers=subdir.find_node(name + '-pch.hpp'),
+                        headers=subdir.find_node(f'{name}-pch.hpp'),
                         use='core-objects LIBRESOLV',
                         includes=name)
             testableObjects.append(srcObjects)
@@ -71,7 +71,7 @@
         bld.program(name=name,
                     target=f'{top}/bin/{name}',
                     source=[mainFile],
-                    use='core-objects ' + srcObjects,
+                    use=f'core-objects {srcObjects}',
                     includes=name)
 
     bld.objects(target='tools-objects',