[Audio] Music not playing during "retro"-part of the intro

[Raffaello Grani]

When starting the game without skipping the intro, the music plays fine right up to the point where the "retro"-part starts with the ISDs looking for the Rebels. From that point onwards, the music stays silent. Briefing, launch sequences and in-flight music are not affected.

(Btw: Nice work on the improved music, Jan.)

[David Esparza Guerrero]

This issue was fixed as part of commit 6e5d332