App: Fix GroupSeparator bug

Elwig/Windows/DeliveryAdminWindow.xaml.cs

@@ -889,7 +889,7 @@ namespace Elwig.Windows {
             p.Acid = (AcidInput.Text == "") ? null : double.Parse(AcidInput.Text);
             p.Comment = (PartCommentInput.Text == "") ? null : PartCommentInput.Text;
 
-            p.Weight = int.Parse(WeightInput.Text.Replace("\u202f", ""));
+            p.Weight = int.Parse(WeightInput.Text.Replace(Utils.GroupSeparator, ""));
             p.ManualWeighing = ManualWeighingInput.IsChecked ?? false;
             p.ScaleId = ScaleId;
             p.WeighingId = WeighingId;