Audio system panic on using Color Picker widget in egui_inspector debugtools

[odecay]

Description

Panic due to unwrapping in menu audio sound effect system on label.

To Reproduce

1. run with `cargo run -- -d
2. press f10 to start egui_inspector
3. select the TextureAtlasSprite component on one of the fighter entities
4. click the color field

Game panics with

thread 'Compute Task Pool (0)' panicked at 'called `Option::unwrap()` on a `None` value', src/audio.rs:105:36
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'task has failed', /home/otis/.cargo/registry/src/github.com-1ecc6299db9ec823/async-task-4.3.0/src/task.rs:426:43

Expected Behavior

Color picker shows, allowing change of color field.

This does happen if main_menu_sounds system is disabled in main.rs.