security: remove deprecated HmacFilter

Change-Id: I27e37724efe83e161ce5b012d83f8f6165a9c7d0
diff --git a/tests/unit/security/transform.t.cpp b/tests/unit/security/transform.t.cpp
index 07958cd..901839b 100644
--- a/tests/unit/security/transform.t.cpp
+++ b/tests/unit/security/transform.t.cpp
@@ -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).
  *
@@ -65,9 +65,6 @@
   transform::DigestFilter* digestFilter = nullptr;
   BOOST_CHECK(digestFilter == nullptr);
 
-  transform::HmacFilter* hmacFilter = nullptr;
-  BOOST_CHECK(hmacFilter == nullptr);
-
   transform::BlockCipher* blockCipher = nullptr;
   BOOST_CHECK(blockCipher == nullptr);