Incorrect combination of Site Settings (related to s3) can bring the site down

[mc0e]

Continuing the discussion from 500 error in AWS s3 code:

@mc0e

Looks like I had SiteSetting.enable_s3_uploads set, which is quite understandably incompatible with not setting SiteSetting.s3_upload_bucket, but it should be handled more gracefully.

My support request has quite reasonably been closed, but it appears that it’s possible to lock oneself out of the admin interface and the entire web site through an incorrect combination of settings, which should be treated as a bug.

[zogstrip]

I just added a fix that will make sure we have set a bucket before enabling backups to S3

https://github.com/discourse/discourse/commit/5277ec1ac07fcddbfb240fb700dcf89b1c0992cb