title: Can't clone private repo on github from SourceTree
body: <p>A similar issue is described <a href="https://stackoverflow.com/q/20718193/2313806">here</a> however, my symptoms are a little different and none of the steps there seemed to work.  Nor does the suggestion <a href="https://stackoverflow.com/q/46999328/2313806">here</a> work.</p>
  
  <p>I'm attempting to use SourceTree to clone a private repo belonging to github organization of which I am a part.  I have full permissions to view and commit to the repo, I can see it online when I log in, AND I can clone just fine with the command line and also via the github desktop application.  It only fails in SourceTree.  </p>
  
  <p>Further, it is not bad credentials or anything like that, because I can clone, commit and push to my other non-private repos on github using SourceTree with my github credentials.</p>
  
  <p>From the "Clone a Repository" dialog I enter the source URL, which looks something like this:</p>
  
  <pre><code>https://github.com/MyOrgName/reponame.git
  </code></pre>
  
  <p>I tab off of that field and it populates the destination path and name fields, but at the bottom of the dialog is a yellow exclamation point with this error:</p>
  
  <pre><code>This is not a valid source path / URL
  </code></pre>
  
  <p>If I click the error message, it brings up the "Details" dialog, which states the following (twice for some reason):</p>
  
  <pre><code>remote: Repository not found.
  fatal: repository 'https://github.com/MyOrgName/reponame.git/' not found
  remote: Repository not found.
  fatal: repository 'https://github.com/MyOrgName/reponame.git/' not found
  </code></pre>
  
  <p>I have also tried this by adding my username to the url like so:</p>
  
  <pre><code>https://myusername@github.com/MyOrgName/reponame.git
  </code></pre>
  
  <p>but no luck there either.</p>