Use SPSCQueue::PopWait in Scripting

src/core/rpc/rpc_server.h

@@ -31,10 +31,7 @@ private:
 
     Server server;
     Common::SPSCQueue<std::unique_ptr<Packet>> request_queue;
-    bool running = false;
     std::thread request_handler_thread;
-    std::mutex request_queue_mutex;
-    std::condition_variable request_queue_cv;
 };
 
 } // namespace RPC