build: make precompiled headers more useful

This can reduce the compilation time of a release
build (without tests) by more than 40%

Refs: #5212
Change-Id: I977aff0c0c7becbfee8a8b55605b81d0c014829b
diff --git a/daemon/face/udp-factory.cpp b/daemon/face/udp-factory.cpp
index 4feec76..331174d 100644
--- a/daemon/face/udp-factory.cpp
+++ b/daemon/face/udp-factory.cpp
@@ -28,6 +28,7 @@
 #include "multicast-udp-transport.hpp"
 #include "common/global.hpp"
 
+#include <boost/lexical_cast.hpp>
 #include <boost/range/adaptor/map.hpp>
 #include <boost/range/algorithm/copy.hpp>