title: A server with the specified hostname could not be found in AFNetworking
body: <p>I switch out <code>AFnetworking</code> API from <code>ASIHTTPRequest</code> in my app for connection error issues.</p>
  
  <p>But now I'm getting connection error in <code>AFNetworking</code>. How can I resolve this?</p>
  
  <pre><code>Printing description of error: Error Domain=NSURLErrorDomain Code=-1003 "A server with the
  specified hostname could not be found." UserInfo=0x1553bab0
  {NSErrorFailingURLStringKey=https://example.com/oauth/token,
  NSErrorFailingURLKey=https://example.com/oauth/token, NSLocalizedDescription=A server
  with the specified hostname could not be found., NSUnderlyingError=0x1553b2c0 "A server
  with the specified hostname could not be found."} (lldb) 
  </code></pre>