add proper #include line for NDNLPv2 tags

refs #3755

Change-Id: Id700ab00722a4e8393ac5013d59f4979086b5064
diff --git a/src/ndn-traffic-client.cpp b/src/ndn-traffic-client.cpp
index d6faaf7..c297446 100644
--- a/src/ndn-traffic-client.cpp
+++ b/src/ndn-traffic-client.cpp
@@ -33,6 +33,7 @@
 #include <ndn-cxx/exclude.hpp>
 #include <ndn-cxx/face.hpp>
 #include <ndn-cxx/name-component.hpp>
+#include <ndn-cxx/lp/tags.hpp>
 #include <ndn-cxx/util/backports.hpp>
 
 #include "logger.hpp"