title: WKWebView.loading returns unrecognized selector
body: <p>I run a timer that looks like this:</p>
  
  <pre><code>else if label == "Instagram" &amp;&amp; defaults.boolForKey("instagramswitch") {
              activeWebview.loadRequest(request)
              let dispatchTime: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
              dispatch_after(dispatchTime, dispatch_get_main_queue(), {
                  self.i = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("instagram:"), userInfo: activeWebview, repeats: true)
              })
  }
  </code></pre>
  
  <p>and the function looks like this:</p>
  
  <pre><code>func instagram(webview: WKWebView) {
      if webview.loading == false {
          let code: String = "document.getElementsByClassName('2yal _csflf').item(3).click();"
          webview.evaluateJavaScript(code, completionHandler: nil)
          let dispatchTime: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
          dispatch_after(dispatchTime, dispatch_get_main_queue(), {
              self.i = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("instagramloaded:"), userInfo: webview, repeats: true)
          })
      }
  }
  </code></pre>
  
  <p>I get an error on this line - "if webview.loading == false {" and the error is:</p>
  
  <p>2016-04-10 15:16:53.679 PF 0.5[878:241174] -[__NSCFTimer isLoading]: unrecognized selector sent to instance 0x145a03fe0</p>
  
  <p>Any and all help would be much appreciated :) I think it is because I call webview.loading but I have no idea why that would cause a crash.</p>