Warning: This async method lacks 'await' operators and will run synchronously.

Hi All,
i am trying hard to have the code posted on http://blogs.msdn.com/b/webdev/archive/2013/10/16/get-more-information-from-social-providers-used-in-the-vs-2013-project-templates.aspx work. 
I have made other posts with no luck at all. This is not actually a duplicate because I am following a different approach. I am used to use VB.net but this time I am using C#.
When I add the following code taken from the tutorial above into my Startup.Auth.cs the system gives me the following warning message:
This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.