SEBWIN-408: Made favicon loading asynchronous.

SafeExamBrowser.Browser/BrowserApplicationInstance.cs

@@ -280,6 +280,8 @@ namespace SafeExamBrowser.Browser
 		}
 
 		private void DisplayHandler_FaviconChanged(string uri)
+		{
+			Task.Run(() =>
 			{
 				var request = new HttpRequestMessage(HttpMethod.Head, uri);
 				var response = httpClient.SendAsync(request).ContinueWith(task =>
@@ -292,6 +294,7 @@ namespace SafeExamBrowser.Browser
 						window.UpdateIcon(Icon);
 					}
 				});
+			});
 		}
 
 		private void DisplayHandler_ProgressChanged(double value)