title: UrlFetchApp muteHttpException doesn't work
body: <p>How to handle urlfetch error? I'am trying <code>muteHttpExceptions: true</code>, but it doesn't work and the script breaks.</p>
  
  <pre><code>function myFunction() {
    var result = UrlFetchApp.fetch("http://www.soccer-wallpapers.net/soccer_wallpaper/barcelona_fc_barcelona_360.jpg ", {
  muteHttpExceptions: true });
    Logger.log("code: " + result.getResponseCode());
    Logger.log("text: " + result.getContentText());
  }
  </code></pre>
  
  <p>But I'm trying another error url to work fine.</p>
  
  <pre><code>http://img8.uploadhouse.com/fileuploads/2058/20586362b34151eb10a4001e1c44305fe41bff6.jpg
  </code></pre>
  
  <p>Solved handle using the try and catch method.</p>
  
  <pre><code>  try
    {
      var page = UrlFetchApp.fetch("http://www.soccer-wallpapers.net/soccer_wallpaper/barcelona_fc_barcelona_360.jpg");
    }
    catch(err)
    {
      Browser.msgBox("error");
    }
  }
  </code></pre>