Fixed a crash on "split to parts" with an active SLA printer.
Fixed a crash on "split to parts" with an active SLA printer.

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