Favicons for feeds don't work without an S3 Bucket

[rach-sharp]

Favicons for feeds are stored in an S3 bucket at the moment. Worth looking into possible ways to decouple from S3, maybe with a container that can act as S3 if that exists, or by storing the favicons for feeds in some other way?

[norweeg]

Import of opml also fails without an S3

[angristan]

See https://github.com/rach-sharp/freedbin/issues/13#issuecomment-585224049