[kankan] Doesn't work.

[ghost]

• I've verified and I assure that I'm running youtube-dl 2018.01.14

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• At least skimmed through the README, most notably the FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones

What is the purpose of your issue?

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
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http://yinyue.kankan.com/vod/51/51801.shtml

ERROR: Unable to download webpage: <urlopen error [Errno -3] Temporary failure in name resolution> (caused by URLError(gaierror(-3, 'Temporary failure in name resolution'),))
  File "/usr/lib/python3/dist-packages/youtube_dl/extractor/common.py", line 517, in _request_webpage
    return self._downloader.urlopen(url_or_request)
  File "/usr/lib/python3/dist-packages/youtube_dl/YoutubeDL.py", line 2198, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/usr/lib/python3.6/urllib/request.py", line 526, in open
    response = self._open(req, data)
  File "/usr/lib/python3.6/urllib/request.py", line 544, in _open
    '_open', req)
  File "/usr/lib/python3.6/urllib/request.py", line 504, in _call_chain
    result = func(*args)
  File "/usr/lib/python3/dist-packages/youtube_dl/utils.py", line 933, in http_open
    req)
  File "/usr/lib/python3.6/urllib/request.py", line 1320, in do_open
    raise URLError(err)