core: use ndn-cxx's getRandomNumberEngine()

Change-Id: I3b5b3ac5238d47ac14481b21d0303c63d0c93b56
diff --git a/daemon/fw/strategy.cpp b/daemon/fw/strategy.cpp
index 4dfe32e..3f364ea 100644
--- a/daemon/fw/strategy.cpp
+++ b/daemon/fw/strategy.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018,  Regents of the University of California,
+ * Copyright (c) 2014-2019,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -26,7 +26,6 @@
 #include "strategy.hpp"
 #include "forwarder.hpp"
 #include "core/logger.hpp"
-#include "core/random.hpp"
 
 #include <boost/range/adaptor/map.hpp>
 #include <boost/range/algorithm/copy.hpp>