mod_c2s_conn_throttle: Reduce log level from error->info Our general policy is that "error" should never be triggerable by remote entities, and that it is always about something that requires admin intervention. This satisfies neither condition. The "warn" level can be used for unexpected events/behaviour triggered by remote entities, and this could qualify. However I don't think failed auth attempts are unexpected enough. I selected "info" because it is what is also used for other notable session lifecycle events.

Over the years, some servers stop working for various reasons, and leave
behind broken roster subscriptions that trigger failing s2s connections.
This module allows cleaning up such cases by unsubscribing local users
from their contacts on those servers. Also works for typos and the like.
Use with care.

```lua
Component "gmail.com" "unsubscriber"
```