'abort' 事件
稳定性: 0 - 弃用. Listen for
'close' event 。当请求被客户端中止时触发。
此事件仅在第一次调用 abort() 时触发。
Stability: 0 - Deprecated. Listen for the
'close' event instead.Emitted when the request has been aborted by the client. This event is only
emitted on the first call to abort().