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

Also remove redundant includes.

Change-Id: I0e1f55abcf852b95a4fd8c9a0e3a30aa153f892c
diff --git a/src/util/notification-subscriber.hpp b/src/util/notification-subscriber.hpp
index 9387a24..be36d31 100644
--- a/src/util/notification-subscriber.hpp
+++ b/src/util/notification-subscriber.hpp
@@ -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,
@@ -34,7 +34,6 @@
 #include "time.hpp"
 #include "scheduler.hpp"
 #include "scheduler-scoped-event-id.hpp"
-#include <boost/concept_check.hpp>
 
 namespace ndn {
 namespace util {