mod_ping_muc: Delay ping a configurable amount of time If a server is restarting, checking immediately before it has a chance to complete its restart and get ready would often fail, preventing the possibility of transparent restarts as supported by Prosody's mod_muc. Reconnecting immediately when a connection is closed for being idle, or because the remote server is trying to reclaim some resources, is also counter-productive as the connection may fail. Also, if there is some Internet routing problem affecting s2s, it may help to wait a bit before checking, in case the problem resolved itself in the mean time.

This module allows advertising a machine-readable document were outages,
planned or otherwise, may be reported.

See [XEP-0455: Service Outage Status] for further details, including
the format of the outage status document.

```lua
modules_enabled = {
    -- other modules
    "service_outage_status",
}

outage_status_urls = {
    "https://uptime.example.net/status.json",
}
```

The outage status document should be hosted on a separate server to
ensure availability even if the XMPP server is unreachable.