Optimize latency and IP address information testing

If the first test fails, it will be tested again after 500ms.

v2rayN/ServiceLib/ViewModels/StatusBarViewModel.cs

@@ -316,6 +316,8 @@ namespace ServiceLib.ViewModels
                 return;
             }
 
+            _updateView?.Invoke(EViewAction.DispatcherServerAvailability, ResUI.Speedtesting);
+
             var msg = await (new UpdateService()).RunAvailabilityCheck();
 
             NoticeHandler.Instance.SendMessageEx(msg);