core: move nfd-specific files to daemon/

Refs: #4922
Change-Id: I2243dbb87c63f9cbaf7d7051d7a0d4bca2f9fdb5
diff --git a/daemon/face/multicast-udp-transport.cpp b/daemon/face/multicast-udp-transport.cpp
index 2c61527..689b7e0 100644
--- a/daemon/face/multicast-udp-transport.cpp
+++ b/daemon/face/multicast-udp-transport.cpp
@@ -27,7 +27,7 @@
 #include "socket-utils.hpp"
 #include "udp-protocol.hpp"
 
-#include "core/privilege-helper.hpp"
+#include "common/privilege-helper.hpp"
 
 #include <boost/functional/hash.hpp>