Abovehead Chat indicator sometimes turns back on, even if preference is off.

### Testmerges

#3073: 'Squad Team Leader' by morrowwolf at commit 55a7eaf7ac #3088: 'Fixes offset issue for multithreading test' by LynxSolstice at commit 95d6c01a9c #2652: 'Say\Hearing performance 515 edition' by Git-Nivrak at commit 0c8a0b70a3 #3179: 'Dancer buff + Bug Fixes' by Git-Nivrak at commit 3985fd08a6 #3185: 'GAU buff. ' by Tisx1 at commit c75cbb5947 #3192: 'discord certification' by harryob at commit 46c90b2253

### Description of the bug

The abovehead chat indicator sometimes turns "on", even though the preference is disabled. This started happening around when TGUI chat got merged I believe. The bandaid fix for this is turning it back on and off again, which means this is clearly a bug.

### What's the difference with what should have happened?

Abovehead Chat Indicator preference should not reenable when disabled.

### How do we reproduce this bug?

1. Not sure what causes it.

- Sometimes it happens when you die and respawn,
- sometimes it happens when you join/reconnect to the game.

All i know is it happens a LOT
...

### Issue Bingo

- [X] Issue could be reproduced at least once
- [X] Issue happened in a recent (less than 7 days ago) round
- [X] Couldn't find an existing issue about this (https://github.com/cmss13-devs/cmss13/issues)