title: WKWebView catch HTTP error codes
body: <p>When i return any http error from my page (currently 401, but i tried also with 404 and so on)</p>
  
  <p><a href="http://min60.com/__personal/e401.php">http://min60.com/__personal/e401.php</a></p>
  
  <p>the delegate callbacks of the WKWebView don't return an error</p>
  
  <pre><code>- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error
  
  - (void)webView:(WKWebView *)webView didFailNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error {
  </code></pre>
  
  <p>How to catch such errors?</p>