Fixed a bug with erase of the multiple instance selection in 3D-scene

+ Try to fix accidentally crash on Copy/Paste

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -3952,6 +3952,8 @@ void ObjectList::select_items(const wxDataViewItemArray& sels)
 {
     m_prevent_list_events = true;
 
+    m_last_selected_item = sels.empty() ? wxDataViewItem(nullptr) : sels.back();
+
     UnselectAll();
     SetSelections(sels);
     part_selection_changed();