Fix: No Endless loop from logout

src/STS/Controllers/HomeController.cs

@@ -55,6 +55,10 @@ namespace Coscine.Api.STS.Controllers
                         // Will redirect to root/home page
                         ViewBag.Redirect = "/";
                     }
+                    if (string.IsNullOrWhiteSpace(ViewBag.Redirect))
+                    {
+                        ViewBag.Redirect = "/";
+                    }
                 }
 
                 var dictionary = new Dictionary<string, string>