security: stop installing headers of concrete PIB, TPM, and KeyHandle implementations

Refs: #4782
Change-Id: I23bb75c485034140f29b10bd3a103f4aa480be4b
diff --git a/tests/unit/security/tpm/back-end-wrapper-mem.hpp b/tests/unit/security/tpm/back-end-wrapper-mem.hpp
index a8b44fc..67dd7e0 100644
--- a/tests/unit/security/tpm/back-end-wrapper-mem.hpp
+++ b/tests/unit/security/tpm/back-end-wrapper-mem.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2019 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,7 +22,7 @@
 #ifndef NDN_TESTS_SECURITY_TPM_BACK_END_WRAPPER_MEM_HPP
 #define NDN_TESTS_SECURITY_TPM_BACK_END_WRAPPER_MEM_HPP
 
-#include "ndn-cxx/security/tpm/back-end-mem.hpp"
+#include "ndn-cxx/security/tpm/impl/back-end-mem.hpp"
 
 namespace ndn {
 namespace security {