在上传之前对图片做下处理~！
if (tempImage.imageOrientation != UIImageOrientationUp) {
UIGraphicsBeginImageContextWithOptions(tempImage.size, NO, tempImage.scale);
[tempImage drawInRect:(CGRect){0,0,tempImage.size}];
UIImage *normalizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
tempImage = normalizedImage;
}
