* feat: config option object_storage.max_attempts
Backblaze recommends to have a high amount of attempts since they've
designed their architecture so that it will return 5xx errors to
indicate that the client should do a new attempt.
https://www.backblaze.com/blog/b2-503-500-server-error/closes#6415
* Rephrase comment
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Co-authored-by: Chocobozzz <me@florianbigard.com>