Try to copy the local NSMutableDictionary before calling CGImageSourceCreateImageAtIndex, try to solve the rare crash inside ImageIO call stack.
Try to copy the local NSMutableDictionary before calling CGImageSourceCreateImageAtIndex, try to solve the rare crash inside ImageIO call stack.

rs/SDWebImage,tualatrix/SDWebImage,dreampiggy/SDWebImage,dreampiggy/SDWebImage,dreampiggy/SDWebImage