Crash after deleting the last physical printer

[DominikPalo]

Description of the bug

PrusaSlicer crashed after deleting the last physical printer.

Crash stack trace:

Thread 0 Crashed:: slic3r_main Dispatch queue: com.apple.main-thread
0   PrusaSlicer                   	       0x1035cb738 Slic3r::GUI::MainFrame::show_printer_webview_tab(Slic3r::DynamicPrintConfig*) + 112
1   PrusaSlicer                   	       0x10371f544 Slic3r::GUI::Tab::load_current_preset() + 248
2   PrusaSlicer                   	       0x1037185c0 Slic3r::GUI::Tab::select_preset(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, bool, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&) + 4292
3   PrusaSlicer                   	       0x10365bacc Slic3r::GUI::PresetComboBox::selection_is_changed_according_to_physical_printers() + 812
4   PrusaSlicer                   	       0x10374108c std::__1::__function::__func<Slic3r::GUI::Tab::create_preset_tab()::$_1, std::__1::allocator<Slic3r::GUI::Tab::create_preset_tab()::$_1>, void (int)>::operator()(int&&) + 40
5   PrusaSlicer                   	       0x10366357c Slic3r::GUI::TabPresetComboBox::OnSelect(wxCommandEvent&) + 336

Full crash report: prusaslicer-crash.txt

Project file & How to reproduce

1. Go to the "Printers" tab
2. Ensure there is only one printer remaining under "Physical Printers" (I was removing all physical printers one by one, so in my case, it was the last printer preset).
3. Try to delete that printer preset by clicking on the (X) icon
4. The app crashes

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

Version 2.9.0

Operating system

macOS Sequoia 15.1.1 (24B91)

Printer model

N/A