mod_s2sout_override: New module for overriding s2s connections This takes advantage of the new event added in Prosody rev d5f322dd424b which enables a cleaner way to override the connection using a resolver.

This module lets you block connections to remote servers at the s2s
level.

``` {.lua}
modules_enabled = {
    -- other modules --
    "s2s_blacklist",

}
s2s_blacklist = {
    "proxy.eu.jabber.org",
}
```