Sounds should be stopped when they are disabled in options screen

[supertuxkart-sourceforge-migration]

Author: deveee

To reproduce:

• score a goal in soccer mode
• a while after goal press escape and disable sounds in options
• when you will enable sounds after 1-2 minutes, you will hear this paused goal sound. It's outdated and shouldn't be played of course.

The same situation is with other sounds, but score goal sound is the longest and it's most noticable there.

Migrated-From: https://sourceforge.net/apps/trac/supertuxkart/ticket/1091