title: The ServicePointManager does not support proxies with the net4bsl.bsl.co.uk scheme
body: <p>I get this error when trying to sync a team project on team foundation serer in visual studio 2017 at work</p>
  
  <pre><code>Git failed with a fatal error.
  
  NotSupportedException encountered.
  
     The ServicePointManager does not support proxies with the net4bsl.bsl.co.uk scheme.
  
  cannot spawn /c/program files (x86)/microsoft visual studio/2017/community/common7/ide/commonextensions/microsoft/teamfoundation/team explorer/Git/mingw32/libexec/git-core/git-askpass.exe: No such file or directory
  
  could not read Username for 'https://ams-british-steel.visualstudio.com': terminal prompts disabled
  </code></pre>
  
  <p>This is what I have configred as my proxy</p>
  
  <pre><code>git config --global http.proxy net4bsl.bsl.co.uk:8080
  </code></pre>
  
  <p>Any ideas?</p>