selenium _WaitForSingleObject(self._handle, 0) == _WAIT_OBJECT_0

在關閉driver時，如果用close,而不是用quit,會出現如下錯誤：

Exception ignored in: <bound method Popen.__del__ of <subprocess.Popen object at 0x0000027A6CAD1278>>
Traceback (most recent call last):
File "E:\python36\lib\subprocess.py", line 768, in __del__
self._internal_poll(_deadstate=_maxsize)
File "E:\python36\lib\subprocess.py", line 1035, in _internal_poll
if _WaitForSingleObject(self._handle, 0) == _WAIT_OBJECT_0:
OSError: [WinError 6] 句柄無效。

原因，close只關閉當前window，而quit才能退出整個driver，