I saw the same thing while using 4.13 Beta. I have since gone back to the current release 4.12. but it still does it sometimes. I just kill the upload and that removes it. I don't think it's anything to worry about.
Though I can see how it could be a problem if you've downloaded something for example "Porn". That might be embarrassing if it showed up at the wrong time........It should quit on it's own eventually
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