Fix grid Rows/columns editor

Author: jogibear9988

WpfDesign.Designer/Project/PropertyGrid/Editors/FlatCollectionEditor.xaml.cs

@@ -86,6 +86,7 @@ public void LoadItemsCollection(DesignItemProperty itemProperty)
 			}
 
 			ListBox.ItemsSource = _itemProperty.CollectionElements;
+			LoadItemsCombobox();
 		}
 
 		public void LoadItemsCombobox()

WpfDesign.Designer/Project/PropertyGrid/Editors/OpenCollectionEditor.xaml.cs

@@ -53,7 +53,6 @@ void open_Click(object sender, RoutedEventArgs e)
 
 			var editor = new FlatCollectionEditor();
 			editor.LoadItemsCollection(node.FirstProperty);
-			editor.LoadItemsCombobox();
 			editor.ShowDialog();
 		}
 	}