[zeditor] crash-to-desktop in Debug mode when playing Wind Fish ambient music

Steps to recreate:

[LIST=1]
[*]Open ZeldaClassic.sln in Microsoft Visual Studio
[*]Set a breakpoint at the { of body of playTune(int32_t) in zquest.cpp
[*]F5 (Debug->Start Debugging)
[*]Etc->Media->Ambient Music->Wind Fish
[*]F5 (Debug->Continue)
[*]ASSERT(new_speed_secs > 0); fails in al_set_timer_speed
[/LIST]