UI: Update volmeters at 60hz

Technically this is 62.5Hz (once every 16ms) but who's counting?

UI/volume-control.cpp

@@ -562,7 +562,8 @@ VolumeMeter::VolumeMeter(QWidget *parent, obs_volmeter_t *obs_volmeter,
 	updateTimerRef = updateTimer.toStrongRef();
 	if (!updateTimerRef) {
 		updateTimerRef = QSharedPointer<VolumeMeterTimer>::create();
-		updateTimerRef->start(34);
+		updateTimerRef->setTimerType(Qt::PreciseTimer);
+		updateTimerRef->start(16);
 		updateTimer = updateTimerRef;
 	}