修正下拉刷新图片缩放比例

GMRefresh/Classes/GMRefreshHeader.m

@@ -76,9 +76,10 @@
             // pullingPercent 超过 1 时，位置固定
             self.gifView.hidden = NO;
             CGFloat translation = self.mj_h * 1 / 2;
+            CGFloat scale = MIN(1.0, pullingPercent);
 
             _prepareImageView.transform = CGAffineTransformMakeTranslation(0, -translation);
-            _prepareImageView.transform = CGAffineTransformScale(_prepareImageView.transform, pullingPercent, pullingPercent);
+            _prepareImageView.transform = CGAffineTransformScale(_prepareImageView.transform, scale, scale);
         }
     }
 }