security: dissolve private header security/impl/openssl.hpp

It no longer serves a purpose

Change-Id: Ic145460c139dbda969976644352fed3f44fd32ec
diff --git a/tools/ndnsec/import.cpp b/tools/ndnsec/import.cpp
index 2fb6755..c25b0c7 100644
--- a/tools/ndnsec/import.cpp
+++ b/tools/ndnsec/import.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2021 Regents of the University of California.
+ * Copyright (c) 2013-2022 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,9 +22,10 @@
 #include "ndnsec.hpp"
 #include "util.hpp"
 
-#include "ndn-cxx/security/impl/openssl.hpp"
 #include "ndn-cxx/util/scope.hpp"
 
+#include <openssl/crypto.h>
+
 namespace ndn {
 namespace ndnsec {