Music widget does some polling even if muted

[sprunk]

There is some sort of polling every 0.03s going on regardless of whether music is muted. Doesn't seem to do much harm other than waste a bit of perf but maybe there's other mistaken assumptions to uncover?

Zero-K/LuaUI/Widgets/snd_music2.lua

Lines 336 to 339 in b9f90e0

	timeframetimer_short = timeframetimer_short + dt
	if timeframetimer_short > 0.03 then
	local playedTime, totalTime = Spring.GetSoundStreamTime()
	playedTime = tonumber( ("%.2f"):format(playedTime) )