Adjust includes for the updated locations of ndn-cxx security headers

Change-Id: I788d56cee45aae9f7ce5d15320395d3d591f7e61
diff --git a/src/ca-config.hpp b/src/ca-config.hpp
index 0186067..091c327 100644
--- a/src/ca-config.hpp
+++ b/src/ca-config.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2017-2019, Regents of the University of California.
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,7 @@
 
 #include "certificate-request.hpp"
 #include "client-config.hpp"
-#include <ndn-cxx/security/v2/certificate.hpp>
+#include <ndn-cxx/security/certificate.hpp>
 
 namespace ndn {
 namespace ndncert {