Fixed debug crash in update_changed_tree_ui
Fixed debug crash in update_changed_tree_ui

Reproduce: For MK2.5S printer preset set flag "Support stealth mode"

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