title: Android repository sdk update site not working
body: <p>I want to update sdk build tools to 27.0.3 but i dont get any updates at sdk manager.</p>
  
  <p><a href="https://i.stack.imgur.com/XcFKh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XcFKh.png" alt="27.0.3 is not in list"></a></p>
  
  <p>Besides "Android Repository" in "SDK Update Sites" tab is disabled with the below error :</p>
  
  <pre><code>DOCTYPE is disallowed when the feature "http://apache.org/xml/features/disallow_doctype_decl" set to true.
  </code></pre>
  
  <p>A screenshot :</p>
  
  <p><a href="https://i.stack.imgur.com/xfWLy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xfWLy.png" alt="The Error"></a></p>
  
  <p>What is the problem? How can i update SDK stuffs?
  Using Android Studio 3.0.1 btw.</p>