update mem leak in crypto helpers

Change-Id: Id9294dba9f1f2639edc58b5112b619eeee80af55
diff --git a/src/ca-module.hpp b/src/ca-module.hpp
index 0e6ea06..e1cedaf 100644
--- a/src/ca-module.hpp
+++ b/src/ca-module.hpp
@@ -22,7 +22,7 @@
 #define NDNCERT_CA_MODULE_HPP
 
 #include "configuration.hpp"
-#include "detail/crypto-helper.hpp"
+#include "detail/crypto-helpers.hpp"
 #include "detail/ca-storage.hpp"
 
 namespace ndn {