S3 compatible Backups

[InsOpDe]

I find the backup solution rather sparse. Would it be possible to introduce another environment variable which lets you set the S3-Endpoint? Like so:

    - AWS_REGION=eu-central-1
    - AWS_ENDPOINT=https://s3.eu-central-1.wasabisys.com
    - AWS_ACCESS_KEY_ID=some-id
    - AWS_SECRET_ACCESS_KEY=some-secret
    - WALE_S3_PREFIX=mattermost-backups

Now all compatible storage solutions, compatible to the S3-API are able to be used.