Removed unused using statement

Author: Arlodotexe

Microsoft.Toolkit.Uwp.UI.Controls.Media/ImageCropper/ImageCropper.Logic.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Net;
 using System.Numerics;
 using Windows.Foundation;
 using Windows.UI.Xaml;