Change for...of to for...in

[Baystef]

At the busboy.on('finish') event, looping the uploads object with for...of will throw a "uploads is not iterable" error because for...of does not work on objects. The correct for-loop to use here will be for...in

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[Baystef]

@googlebot I signed it!

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[ace-n]

@Baystef thanks for the fix! 🙂