Fix compilation with Boost 1.65.0

Change-Id: Ib88b7e13bddb1728dd882c086e97edffdd696f0d
Refs: #4258
diff --git a/tools/ndn-autoconfig-server/main.cpp b/tools/ndn-autoconfig-server/main.cpp
index 3806d9a..ba836db 100644
--- a/tools/ndn-autoconfig-server/main.cpp
+++ b/tools/ndn-autoconfig-server/main.cpp
@@ -1,5 +1,5 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
+/*
  * Copyright (c) 2014-2017,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
@@ -26,6 +26,8 @@
 #include "program.hpp"
 #include "core/extended-error-message.hpp"
 #include "core/version.hpp"
+
+#include <iostream>
 #include <unistd.h>
 
 namespace ndn {