
Commit 75f131da02c00027b9a8240fb74d117cb0f9d9cf added `chown 'nginx:nginx' '/var/lib/acme'` to the pre-start script, but since it doesn't use `chown -R`, it is possible that there are older existing subdirs (like `acme-challenge`) that are owned to `root` from before that commit went it.
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