mod_http_oauth2: Specify that 'contacts' items are emails in client registration Not enforced, but good for documentation. > Array of strings representing ways to contact people responsible for > this client, typically email addresses. "typically" isn't a great word in a specification, so one could persume this may be e.g. URLs like https://example.com/contact-us or so as well.

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"
```