Fix #3477 Unintended Deletion
Fix #3477 Unintended Deletion

- original fix for #3477 presented message box for each
  inactive selected item.  Now it presents 1 message box
  per document, like the check for deletion of linked
  objects.

Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master