Looks good, some small issues only.

Exclude 100% discount

I think we also need to check:

• We don't have 100% discount set (because there would be no payments for those accounts)
• There aren't any 'award' transactions (because again, no payments in that case maybe)

Addressed comments, exclude users that have any payments, add mode to delete suspended instead of degraded accounts

• Merge branch 'master' into dev/files-quota
• Fix duplicate entries on the files list when reloading it after multi-file upload

I'm not sure why we have to check for enabled languages at all tbh. (I think it would be sufficient to only show enabled languages available for selection in the ui, but not prevent accessing any language). But this fine too.

• Add detailed tests

• Fix Quota::limit() result
• Add quota limit info to fs:quota-usage output
• Improve DAV authentication code, and some other fixes
• Add migration script

Used for testing

• Fix displaying quota error in UI on file upload
• Add test
• Add test

Another more problematic consequence of increasing CONNECTION_MAX_AGE_DAYS is that this increases the window within which a spammer can re-send a message and succeed. Given that we don't fingerprint the message, it also doesn't have to be the same message.