Compilation fixes after upgrade to NFD 0.6.6 and removal of old-style CS

Change-Id: I5472ae71675d8419d8d6c70990182ef028803087
diff --git a/examples/ndn-simple-wifi.cpp b/examples/ndn-simple-wifi.cpp
index 3d6891e..d89db34 100644
--- a/examples/ndn-simple-wifi.cpp
+++ b/examples/ndn-simple-wifi.cpp
@@ -105,7 +105,8 @@
   ndn::StackHelper ndnHelper;
   // ndnHelper.AddNetDeviceFaceCreateCallback (WifiNetDevice::GetTypeId (), MakeCallback
   // (MyNetDeviceFaceCallback));
-  ndnHelper.SetOldContentStore("ns3::ndn::cs::Lru", "MaxSize", "1000");
+  ndnHelper.setPolicy("nfd::cs::lru");
+  ndnHelper.setCsSize(1000);
   ndnHelper.SetDefaultRoutes(true);
   ndnHelper.Install(nodes);