title: Simple tunnel build fails - NEAppProxyErrorDomain
body: <p>I downloaded the last version of SimpleTunnel.</p>
  
  <p><a href="https://developer.apple.com/library/content/samplecode/SimpleTunnel/Introduction/Intro.html#//apple_ref/doc/uid/TP40016140-Intro-DontLinkElementID_2" rel="nofollow noreferrer">https://developer.apple.com/library/content/samplecode/SimpleTunnel/Introduction/Intro.html#//apple_ref/doc/uid/TP40016140-Intro-DontLinkElementID_2</a></p>
  
  <p>I have Xcode 8.1.</p>
  
  <p>When I try to build that project I receive 2 times the error <code>"Use of undeclared type 'NEAppProxyErrorDomain'"</code> in <strong>ClientAppProxyConnection</strong> file, in these lines:</p>
  
  <pre><code>func handleErrorCondition(_ flowError: NEAppProxyErrorDomain? = nil, notifyServer: Bool = true) {
  
  func closeConnection(_ direction: TunnelConnectionCloseDirection, flowError: NEAppProxyErrorDomain?) {
  </code></pre>
  
  <p>I tried to clean the project and rebuild them several times, and I deleted the entire project and downloaded again, etc...</p>
  
  <p>What can I do?</p>
  
  <p>Regards,</p>