Code style: Replace tab with space.
diff --git a/include/ndn-cpp/security/certificate/identity-certificate.hpp b/include/ndn-cpp/security/certificate/identity-certificate.hpp
index 41035a7..e9e90f5 100644
--- a/include/ndn-cpp/security/certificate/identity-certificate.hpp
+++ b/include/ndn-cpp/security/certificate/identity-certificate.hpp
@@ -7,7 +7,7 @@
  */
 
 #ifndef NDN_IDENTITY_CERTIFICATE_HPP
-#define	NDN_IDENTITY_CERTIFICATE_HPP
+#define NDN_IDENTITY_CERTIFICATE_HPP
 
 #include "certificate.hpp"