prevent zun's mutex from resetting the config

[DankRank]

me when I accidentally start the game twice and then the next time it runs in full screen and resizes all my windows:

[ManDude]

yes plz this happens all the time with pcb

[32th-System]

Turns out the reason why this happens is because ZUN will do the mutex checking before loading the cfg, but always write the cfg on exit, even if no cfg was loaded