MKRAVplayer 添加即将切换播放资源代理方法

MKRRadioManager/Classes/MKRRadioManager/MKRAVPlayer/MKRAVPlayer.h

@@ -140,7 +140,7 @@ typedef enum : NSUInteger {
  */
 @property (nonatomic, assign) NSInteger currentIndex;
 
-@property (nonatomic, assign) id <MKRRadioResorce> currentResource;
+@property (nonatomic, strong) id <MKRRadioResorce> currentResource;
 
 /**
  是否正在播放中