keyboard interrupt handler added

app.py

@@ -208,12 +208,15 @@ def main(_argv) -> int:
                                               io_loop))
     thread = Thread(target=io_loop.run_forever)
     thread.start()
+    try:
         while True:
             command = input().strip().lower()[:1]
             if command == "q":
                 stop_server(ws_client, packet_logger, io_loop)(None, None)
                 thread.join()
                 break
+    except KeyboardInterrupt:
+        stop_server(ws_client, packet_logger, io_loop)(None, None)
     return 0