If image (DOES NOT EXIST) AND (maxWidth/maxHeight) ARE set, the stream never closes

If image (DOES NOT EXIST) AND (maxWidth/maxHeight) ARE set, the stream never closes and there is endless waiting for the image. Especially a problem when trying to get images in a FutureBuilder or when doing a retry to get the image again, nothing happens as an image streamlistener is already running.

This is in the context of a `CachedNetworkImageProvider`.

Removing (maxWidth/maxHeight) solves the issue. Then the stream closes and things work as they should.

从 CachedNetworkImageProvider 开始，在设置了 maxWidth 或 maxHeight 时复现图像缺失的问题。确认图像流已关闭，并且 FutureBuilder 或重试可以再次请求图像，而不会被现有的 listener 阻塞。

由索引模型根据 Issue 内容生成。