Better auto-backup options

[zogstrip]

@ky_metro

Option to backup database only (no files). This option is available already for manual backups. It saves a lot of space for file-heavy sites, and allows more backups to be stored locally.

It’s now available through the “backup_with_uploads” site setting

https://github.com/discourse/discourse/commit/de95573d2389099b754869f511bd18515c47e53e