title: getting error when trying to encode HTML page with uft8 using Swift 4
body: <p>I used this code to get html content and it worked for most sites ..this code gave me problem with the site below (which I need! ) I don't know why ! 
  code gave me : </p>
  
  <blockquote>
    <p>Error: Error Domain=NSCocoaErrorDomain Code=261 "The file “d-0002.htm” couldn’t be opened using text encoding Unicode (UTF-8)." UserInfo={NSURL=<a href="http://www.mktbtk.com/dir/nab/2/d-0002.htm" rel="nofollow noreferrer">http://www.mktbtk.com/dir/nab/2/d-0002.htm</a>, NSStringEncoding=4}</p>
  </blockquote>
  
  <pre><code>let myURLString = "http://www.mktbtk.com/dir/nab/2/d-0002.htm"
  
  guard let myURL = URL(string: myURLString) else {
          print("Error: \(myURLString) doesn't seem to be a valid URL")
          return
      }
  
      do {
          let myHTMLString = try String(contentsOf: myURL, encoding: .utf8)
          print("HTML : \(myHTMLString)")
      } catch let error {
          print("Error: \(error)")
      }
  </code></pre>
  
  <p>Note :when I use ascii encoding it worked .. but the content is in Arabic so I need utf8 .. can anyone help </p>