Moderation: fetching down server doesn't display readable error
Steps to reproduce
Add a domain in the moderation panel that is down or not a funkwhale server will display a tooltip with the whole error message, which is not human readable, see screenshot.
What is expected?
I think more human readable error message should be displayed, like "This server is not reachable" or "This is not a Funkwhale server" etc.
Context
Funkwhale version(s) affected: 0.18, dev