src: minor updates to common.hpp and common-pch.hpp

Also remove redundant includes.

Change-Id: I0e1f55abcf852b95a4fd8c9a0e3a30aa153f892c
diff --git a/src/util/logger.cpp b/src/util/logger.cpp
index 04ad954..8cb7d80 100644
--- a/src/util/logger.cpp
+++ b/src/util/logger.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 Regents of the University of California.
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -26,7 +26,6 @@
 
 #include <cinttypes>
 #include <stdio.h>
-#include <type_traits>
 
 namespace ndn {
 namespace util {