Spreadsheet: fix #3474 cross-CS drag-drop issue
Spreadsheet: fix #3474 cross-CS drag-drop issue

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