security: CertificateExtension: Temporarily include stdexcept.
diff --git a/ndn-cpp/security/certificate/certificate-extension.cpp b/ndn-cpp/security/certificate/certificate-extension.cpp
index f0fed8b..aba88dd 100644
--- a/ndn-cpp/security/certificate/certificate-extension.cpp
+++ b/ndn-cpp/security/certificate/certificate-extension.cpp
@@ -6,6 +6,9 @@
  * See COPYING for copyright and distribution information.
  */
 
+#if 1 // TODO: Remove this when we don't throw "not implemented".
+#include <stdexcept>
+#endif
 #include "../../encoding/der/der.hpp"
 #include <ndn-cpp/security/certificate/certificate-extension.hpp>