title: Swift: NSJSONSerialization.JSONObjectWithData returns nil but the json seems ok
body: <p>I use this code to get a JSON, but <code>NSJSONSerialization.JSONObjectWithData</code> returns <code>nil</code>, but the JSON looks ok:</p>
  
  <pre><code>var url = "http://andreid.imcserver.ro/test/service.php"
  var nsURL = NSURL(string: url)
          let task = NSURLSession.sharedSession().dataTaskWithURL(nsURL!){
              (data, response, error) in
              var error: NSError?
              var data2 = NSString(data: data, encoding: NSUTF8StringEncoding)
              println(data)
              println(data2)
  
              var response: NSDictionary? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &amp;error) as? NSDictionary
  
              if let err = error {
                  println("error parsing json")
                  return
              }
  </code></pre>