io: fix bad model index

1 job for master in 1 minute
Status Name Job ID Coverage
  Build
failed build #35332

00:01:00

 
Name Stage Failure
failed
build Build
[6/20] Building CXX object lib/CMakeFiles/libirritator.dir/src/adder.cpp.o
[7/20] Building CXX object app/CMakeFiles/app.dir/src/main.cpp.o
[8/20] Building CXX object app/gui/CMakeFiles/irritator-gui.dir/__/__/external/imgui/imgui.cpp.o
[9/20] Building CXX object lib/CMakeFiles/test-api.dir/test/public-api.cpp.o
[10/20] Building CXX object app/gui/CMakeFiles/irritator-gui.dir/node-editor.cpp.o
ninja: build stopped: subcommand failed.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1