mod_vcard_muc: take roles into account for access check This allows admins on the MUC component to force-set avatars, even if they are not owners in a particular MUC, similar to how they are granted auto-ownership in other contexts.

This module lets you block connections to any remote servers not on a
whitelist.

``` {.lua}
modules_enabled = {
    -- other modules --
    "s2s_whitelist",

}
s2s_whitelist = {
    "example.org",
}
```