Add `cancelCurrentImageLoading` method to UIImageView+WebCache

UIImageView+WebCache.h

@@ -13,5 +13,6 @@
 
 - (void)setImageWithURL:(NSURL *)url;
 - (void)setImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholder;
+- (void)cancelCurrentImageLoading;
 
 @end

UIImageView+WebCache.m

@@ -46,6 +46,11 @@
     }
 }
 
+- (void)cancelCurrentImageLoading
+{
+    [[SDWebImageManager sharedManager] cancelForDelegate:self];
+}
+
 - (void)webImageManager:(SDWebImageManager *)imageManager didFinishWithImage:(UIImage *)image
 {
     self.image = image;