Icons getting corrupted occasionally

[calpaterson]

Description

Occasionally an icon gets corrupted somewhere in the process between download from the web and upload to s3.

Steps to reproduce

Currently unknown but one example in prod is https://quarchive.com/icons/c2149d85-ab15-4c80-b4ff-9a7a841ba7ac.png

1. Do X
2. Then Y
3. And Z

Expected result

An icon

Actual result

Empty file

Additional details