title: 403 when making a request with data post through a tor socks proxy
body: <p>This is my code and the title explain everything what are my mistake?
  my developer is python 3.4
  and I am working in a macos
  I search for uses whit post data and tor socket proxy but no find anything  a trow whidout the proxy works but I need the proxy</p>
  <pre><code>import os,ssl
  if (not os.environ.get('PYTHONHTTPSVERIFY', '') and
  getattr(ssl, '_create_unverified_context', None)):
      ssl._create_default_https_context = ssl._create_unverified_context
  
  if os.name == 'nt':
      import ctypes
      kernel32 = ctypes.windll.kernel32
  
  import  urllib.request
  import socks
  import socket
  
  
  socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS5, &quot;127.0.0.1&quot;, 9050)
  socket.socket = socks.socksocket
  url = 'https://roomlister.stream.highwebmedia.com/session/start/'
  request = urllib.request.Request(url)
  values = {'categories':'f,c','num':'120'}
  data = urllib.parse.urlencode(values)
  data = data.encode() 
  request.add_header('Cache-Control','max-age=0')
  response = urllib.request.urlopen(request,data)
  print (response.read())
  </code></pre>
  <p>the error</p>
  <pre><code>http_error_default
      raise HTTPError(req.full_url, code, msg, hdrs, fp)
  urllib.error.HTTPError: HTTP Error 403: Forbidden
  </code></pre>