Revert MAX() function in `SDImageScaleFactorForKey`
Revert MAX() function in `SDImageScaleFactorForKey`

tualatrix/SDWebImage,awkward/SDWebImage,dreampiggy/SDWebImage,dreampiggy/SDWebImage,dreampiggy/SDWebImage,awkward/SDWebImage,awkward/SDWebImage,rs/SDWebImage,zhang-yawei/SDWebImage