Fixed crash in Plater::priv::can_reload_from_disk()
Fixed crash in Plater::priv::can_reload_from_disk()

prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r,prusa3d/Slic3r