Fixup a77c40f

Since track_ok is used as a loop control, we need to return true if current_track is null
in order to break out, else we get stuck in an infinite loop.

src/sound.cpp

@@ -263,7 +263,7 @@ static bool track_ok(const std::string& id)
 	LOG_AUDIO << "Considering " << id << "\n";
 
 	if(!current_track) {
-		return false;
+		return true;
 	}
 
 	// If they committed changes to list, we forget previous plays, but