fix fastapi support

Author: wang0618

pywebio/platform/fastapi.py

@@ -97,7 +97,7 @@ async def websocket_endpoint(websocket: WebSocket):
                 if text:
                     handler.send_client_data(text)
                 if binary:
-                    handler.send_client_data(text)
+                    handler.send_client_data(binary)
             except WebSocketDisconnect:
                 handler.notify_connection_lost()
                 break