update mem leak in crypto helpers

Change-Id: Id9294dba9f1f2639edc58b5112b619eeee80af55
diff --git a/tests/unit-tests/crypto-helper.t.cpp b/tests/unit-tests/crypto-helper.t.cpp
index 349800f..8f10361 100644
--- a/tests/unit-tests/crypto-helper.t.cpp
+++ b/tests/unit-tests/crypto-helper.t.cpp
@@ -18,7 +18,7 @@
  * See AUTHORS.md for complete list of ndncert authors and contributors.
  */
 
-#include "detail/crypto-helper.hpp"
+#include "detail/crypto-helpers.hpp"
 #include "test-common.hpp"
 
 namespace ndn {