Add support for other s3 compatible services

[grimmy]

I was looking for something like this that I could point to a minio instance, but I see it's currently hard coded to aws. Is there any chance you could add an s3_url parameter to this or would you be open to a pull request making that change?

[LittleFox94]

Hi,
I hacked that into this module, using that in my prosody now - could be useful for other people already, but needs quite some polishing still

https://github.com/LittleFox94/prosody-mod_http_upload_s3/tree/configurable-s3-url