增加了qrCallback中的终止登陆功能

import itchat

def qrCallback(uuid, status, qrcode):
    if status == '400':
        itchat.logout()

itchat.auto_login(True, qrCallback=qrCallback)

if itchat.originInstance.alive:
    itchat.run()
else:
    print('qrcode timeout and exit')