Rename 'src' directory to 'ndn-cxx'

Change-Id: I14394023680901a86977313ca87fb017333614dd
Refs: #3084
diff --git a/tools/ndnsec/util.cpp b/tools/ndnsec/util.cpp
index 6a34f53..b97e934 100644
--- a/tools/ndnsec/util.cpp
+++ b/tools/ndnsec/util.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2017 Regents of the University of California.
+ * Copyright (c) 2013-2018 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -21,7 +21,7 @@
 
 #include "util.hpp"
 
-#include "security/detail/openssl.hpp"
+#include <ndn-cxx/security/detail/openssl.hpp>
 
 namespace ndn {
 namespace ndnsec {