Master Mixer Track Mute button is on when loading empty.mmp

@bratpeki is already working on this.

Since Jan 26, 2026.

### System Information

Manjaro (Arch-based)

### LMMS Version(s)

Nightly

### Most Recent Working Version

LMMS 1.2.2 (thx Spherexx!), but not tested that extensively

### Bug Summary

It happens across the board for most of my projects.

It's only visual, clicking it "unmutes" it. Loading again, even if saved, shows it as muted again.

Uploaded a baseline for testing. [link](https://drive.google.com/file/d/1rA73LM0mZVnMR7q2cIPyCSDnToNeRy0_/view?usp=sharing).

### Expected Behaviour

The buttons doesn't show that the track is muted.
i.e. The mute button on "Master" isn't on.

### Steps To Reproduce

1. Load `empty.mmp` on the lastest nightly.
2. The master mute button is on.

### Logs

_No response_

### Screenshots / Minimum Reproducible Project

_No response_

### Please search the issue tracker for existing bug reports before submitting your own.

- [x] I have searched all existing issues and confirmed that this is not a duplicate.