macosx: Keep weak reference to parent scroll view in vlc sub scroll view

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/views/VLCSubScrollView.h

@@ -28,7 +28,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface VLCSubScrollView : NSScrollView
 
-@property (readwrite, assign) NSScrollView *parentScrollView;
+@property (readwrite, weak) NSScrollView *parentScrollView;
 @property (readwrite, assign) BOOL scrollParentY;
 @property (readwrite, assign) BOOL scrollParentX;
 @property (readwrite, assign) BOOL scrollSelf;