Merge pull request #727 from Hangzhou-Weiyi/master

iPhoneX 剪切图片，最小的时候会有上下的间隔，可上下拖动。

TZImagePickerController/TZImagePickerController/TZImagePickerController.h

@@ -24,6 +24,7 @@
 #define iOS8Later ([UIDevice currentDevice].systemVersion.floatValue >= 8.0f)
 #define iOS9Later ([UIDevice currentDevice].systemVersion.floatValue >= 9.0f)
 #define iOS9_1Later ([UIDevice currentDevice].systemVersion.floatValue >= 9.1f)
+#define iOS11Later ([UIDevice currentDevice].systemVersion.floatValue >= 11.0f)
 
 @protocol TZImagePickerControllerDelegate;
 @interface TZImagePickerController : UINavigationController

TZImagePickerController/TZImagePickerController/TZPhotoPreviewCell.m

@@ -113,6 +113,9 @@
         _scrollView.delaysContentTouches = NO;
         _scrollView.canCancelContentTouches = YES;
         _scrollView.alwaysBounceVertical = NO;
+        if (iOS11Later) {
+            _scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
+        }
         [self addSubview:_scrollView];
         
         _imageContainerView = [[UIView alloc] init];