[2.0.76] Train stop sound plays twice when in GUI and near train stop

[Knifery]

Being near a train stop and having a train stop GUI open simultaneously will cause two instances of [train-stop.ogg] to play at once.

• train-stop.ogg plays when near a train stop
• train-stop.ogg plays when opening train stop GUI

This allows the sound played two times at once, offset by slightly different intervals depending on when the GUI is opened. Can be slightly annoying.

[Donion]

Duplicate. Ref: 119211