util: Fix typo on logging.hpp for include common.hpp.
diff --git a/src/util/logging.hpp b/src/util/logging.hpp
index b668133..ab99010 100644
--- a/src/util/logging.hpp
+++ b/src/util/logging.hpp
@@ -9,7 +9,7 @@
 #ifndef NDN_LOGGING_HPP
 #define NDN_LOGGING_HPP
 
-#include <ndn-cpp//common.hpp>
+#include <ndn-cpp/common.hpp>
 
 #ifdef NDN_CPP_HAVE_LOG4CXX