Code style: replace tabs with spaces
diff --git a/ndn-cpp/encoding/binary-xml-decoder.hpp b/ndn-cpp/encoding/binary-xml-decoder.hpp
index 2848457..d4304b0 100644
--- a/ndn-cpp/encoding/binary-xml-decoder.hpp
+++ b/ndn-cpp/encoding/binary-xml-decoder.hpp
@@ -4,7 +4,7 @@
  */
 
 #ifndef NDN_BINARYXMLDECODER_HPP
-#define	NDN_BINARYXMLDECODER_HPP
+#define NDN_BINARYXMLDECODER_HPP
 
 #include <stdexcept>
 #include "../c/errors.h"