feature: Allow message moderation by moderators only.

src/solid-xmpp-chat.js

@@ -260,6 +260,7 @@ export const SolidXMPPChat = {
       'authentication': this.element.dataset.authentication || 'login',
       'password': idToken,
       'allow_chat_pending_contacts': true,
+      'allow_message_retraction': 'moderator',
       'allow_non_roster_messaging': true,
       'allow_dragresize': false,
       'allow_logout': false,