clean header file include

Change-Id: I5df52db13f964a92bba7cc8659ec6bcc222f5cbb
diff --git a/src/protocol-detail/revoke.hpp b/src/protocol-detail/revoke.hpp
index 665ed11..9f02c43 100644
--- a/src/protocol-detail/revoke.hpp
+++ b/src/protocol-detail/revoke.hpp
@@ -21,9 +21,7 @@
 #ifndef NDNCERT_PROTOCOL_DETAIL_REVOKE_HPP
 #define NDNCERT_PROTOCOL_DETAIL_REVOKE_HPP
 
-#include "../certificate-request.hpp"
-#include "ndn-cxx/encoding/block.hpp"
-#include <ndn-cxx/security/v2/certificate.hpp>
+#include "../request-state.hpp"
 
 namespace ndn {
 namespace ndncert {
@@ -35,7 +33,7 @@
 
   static Block
   encodeDataContent(const std::string& ecdhKey, const std::string& salt,
-                             const CertificateRequest& request,
+                             const RequestState& request,
                              const std::list<std::string>& challenges);
 };