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/tests/daemon/face/tcp-factory.t.cpp b/tests/daemon/face/tcp-factory.t.cpp
index 2547e30..fba95fe 100644
--- a/tests/daemon/face/tcp-factory.t.cpp
+++ b/tests/daemon/face/tcp-factory.t.cpp
@@ -29,6 +29,8 @@
 #include "factory-test-common.hpp"
 #include "tests/daemon/limited-io.hpp"
 
+#include <boost/lexical_cast.hpp>
+
 namespace nfd::tests {
 
 using face::TcpChannel;