Game no longer crashes in edit mode when creating a new polygon

fixes #1361

FRBDK/Glue/GameCommunicationPlugin/GlueControl/Embedded/Editing/SelectionLogic.cs

@@ -587,7 +587,7 @@ void MakePolygonRectangleMinMax(float minXInner, float maxXInner, float minYInne
             {
                 polygon = polygon ?? new PolygonFast();
 
-                polygon.Points = asPolygon.Points.ToList();
+                polygon.Points = asPolygon.Points?.ToList() ?? new List<FlatRedBall.Math.Geometry.Point>();
                 polygon.Position = asPolygon.Position;
                 polygon.RotationMatrix = asPolygon.RotationMatrix;
             }