Code style: Replace tab with space.
diff --git a/include/ndn-cpp/util/signed-blob.hpp b/include/ndn-cpp/util/signed-blob.hpp
index 7d9c4e1..6dac765 100644
--- a/include/ndn-cpp/util/signed-blob.hpp
+++ b/include/ndn-cpp/util/signed-blob.hpp
@@ -8,7 +8,7 @@
  */
 
 #ifndef NDN_SIGNED_BLOB_HPP
-#define	NDN_SIGNED_BLOB_HPP
+#define NDN_SIGNED_BLOB_HPP
 
 #include "blob.hpp"