Fix compilation with Boost 1.65.0

Change-Id: Ib88b7e13bddb1728dd882c086e97edffdd696f0d
Refs: #4258
diff --git a/core/logger-factory.cpp b/core/logger-factory.cpp
index 3c419f1..215b087 100644
--- a/core/logger-factory.cpp
+++ b/core/logger-factory.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2016,  Regents of the University of California,
+/*
+ * Copyright (c) 2014-2017,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -30,6 +30,8 @@
 #include <boost/algorithm/string/case_conv.hpp>
 #include <boost/range/adaptor/map.hpp>
 
+#include <iostream>
+
 #ifdef HAVE_CUSTOM_LOGGER
 #error "This file should not be compiled when custom logger is used"
 #endif