Part: fix compoundfilter's items property tooltip
Part: fix compoundfilter's items property tooltip

reported by chrisb:
https://forum.freecadweb.org/viewtopic.php?f=3&t=28299#p229889
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