title: ProxyAuthentication fails while updating conda
body: <p>I keep getting an error while updating conda:</p>
  
  <p>CondaHTTPError: HTTP 000 CONNECTION FAILED for url <a href="https://repo.anaconda.com/pkgs/r/noarch/repodata.json.bz2" rel="nofollow noreferrer">https://repo.anaconda.com/pkgs/r/noarch/repodata.json.bz2</a>
  Elapsed: -</p>
  
  <p>An HTTP error occurred when trying to retrieve this URL.
  HTTP errors are often intermittent, and a simple retry will get you on your way.</p>
  
  <p>If your current network has <a href="https://www.anaconda.com" rel="nofollow noreferrer">https://www.anaconda.com</a> blocked, please file
  a support request with your network engineering team.</p>
  
  <pre><code>ProxyError(MaxRetryError("HTTPSConnectionPool(host='repo.anaconda.com', port=443): 
  Max retries exceeded with url: 
  /pkgs/r/noarch/repodata.json.bz2 (
      Caused by ProxyError(
          'Cannot connect to proxy.', 
          OSError('Tunnel connection failed: 407 Proxy Authentication Required',)))",
      ),
  )
  </code></pre>
  
  <p>A reportable application error has occurred. Conda has prepared the above report.
  Upload did not complete.</p>
  
  <p>I tried this in the .condarc file</p>
  
  <pre><code>proxy_servers:
    http: http://proxy.corp.local:8080
    https: https://proxy.corp.local:8080
  </code></pre>
  
  <p>and</p>
  
  <pre><code>proxy_servers:
      http: http://user:pass@corp.com:8080
      https: https://user:pass@corp.com:8080
  
  ssl_verify: True
  ssl_verify: False
  </code></pre>
  
  <p>Regards</p>
  
  <p>Bjorn</p>