Incorrect cutsccene music volume

[J. King]

If entering a mission while Dodonna/Ackbar is speaking (during which the briefing music volume is lowered), the launch cutscene music volume will play at a reduced volume, and jump to full during the loading screen.

The music should unconditionally play at full volume. Sound effects (crane, R2 unit, torch, engine drone) during the cutscene are unaffected.

[Andrea Simeone]

[Updated] music in the briefing room is now brought to normal level before loading the cutscenePlayer. Fixes #72

→ <<cset 6b26fe484263>>