use PrefixedLogger in more places

src/IPStackSimulator.hh

@@ -29,6 +29,7 @@ public:
   static uint32_t connect_address_for_remote_address(uint32_t remote_addr);
 
 private:
+  static PrefixedLogger log;
   std::shared_ptr<struct event_base> base;
   std::shared_ptr<Server> game_server;
   std::shared_ptr<ServerState> state;