Previous styles on documentElement are not restored

I had a use case where the `documentElement` had inline styles on it, like so: ``. I noticed that after toggling no-scroll to off, the `overflow-x=hidden` was being wiped out. After checking the code in no-scroll, I found that it's hard-coding the style attributes when `off()` is called. I think that no-scroll should be restoring whatever values were set before `on()` was called, instead of overwriting them.