build: Fix compilation against the latest version of ndn-cxx

Change-Id: Ie19e6432231a586efa9be1975e5601cf78c2dce9
diff --git a/src/main.cpp b/src/main.cpp
index 319e622..a21b0fd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -21,16 +21,18 @@
  * \author Yingdi Yu <yingdi@cs.ucla.edu>
  *
  **/
+
+#include <ndn-cxx/util/scheduler.hpp>
+
 #include "conf-file-processor.hpp"
 #include "logger.hpp"
 #include "nlsr.hpp"
 #include "version.hpp"
 
+// boost needs to be included after ndn-cxx, otherwise there will be conflict with _1, _2, ...
 #include <boost/asio.hpp>
 #include <boost/cstdint.hpp>
 
-#include <ndn-cxx/util/scheduler.hpp>
-
 namespace nlsr {
 
 int