调用startLoad方法会出现此bug

[Henry519]

Trapped uncaught exception 'NSGenericException', reason: '*** Collection <__NSArrayM: 0x60000044a860> was mutated while being enumerated.'
[
0 CoreFoundation 0x000000010df5ed4b __exceptionPreprocess + 171,
1 libobjc.A.dylib 0x0000000112cde21e objc_exception_throw + 48,
2 CoreFoundation 0x000000010dfc7f6c __NSFastEnumerationMutationHandler + 124,
3 WLMaster 0x000000010c46f6f5 -[ZFDownloadManager startLoad] + 1493,
4 WLMaster 0x000000010c46c895 -[ZFDownloadManager downFileUrl:filename:videoId:completeBlock:] + 2229,
5 WLMaster 0x000000010c563acd -[WLVideoCacheManager downloadWithData:completeBlock:] + 1325,
6 WLMaster 0x000000010c562fa5 __63-[WLVideoCacheManager addDownTaskToDispatchSemaphoreWithModle:]_block_invoke + 261,
7 libdispatch.dylib 0x000000011437f978 _dispatch_call_block_and_release + 12,
8 libdispatch.dylib 0x00000001143a90cd _dispatch_client_callout + 8,
9 libdispatch.dylib 0x0000000114388312 _dispatch_queue_override_invoke + 1426,
10 libdispatch.dylib 0x000000011438a385 _dispatch_root_queue_drain + 720,
11 libdispatch.dylib 0x000000011438a059 _dispatch_worker_thread3 + 123,
12 libsystem_pthread.dylib 0x0000000114758712 _pthread_wqthread + 1299,
13 libsystem_pthread.dylib 0x00000001147581ed start_wqthread + 13
]

[ghost]

自己改改了，for循环改改