Backup failed message doesn't mention specific error

[gerhard (Gerhard Schlager)]

Thanks for reporting those issues. I made a small adjustment to include the original error message.

https://github.com/discourse/discourse/pull/12257

@Dannii

Also, I didn’t get any notifications for this message - it’s been sending one a day for ages! Any ideas why?

This was caused by a bug.

https://github.com/discourse/discourse/pull/12255