Use owner namespace to fetch configuration

CHANGES.md

@@ -6,6 +6,7 @@
 - #3700: Fix exception that occurs when optional cp attribute is missing
 - #3730: QR Code doesn't work on dark backgrounds
 - #3769: Don't restrict OMEMO PEP push messages to type `headline`
+- #3791: Fetching pubsub node configuration fails
 - Add approval banner in chats with requesting contacts or unsaved contacts
 - Some fixes regarding manually resized chats in `overlayed` view mode.
 - Replace webpack with [rspack](https://rspack.rs)

src/headless/plugins/pubsub/api.js

@@ -42,7 +42,7 @@ export default {
                         from="${full_jid}"
                         type="get"
                         to="${entity_jid}">
-                    <pubsub xmlns="${Strophe.NS.PUBSUB}"><configure node="${node}"/></pubsub>
+                    <pubsub xmlns="${Strophe.NS.PUBSUB}#owner"><configure node="${node}"/></pubsub>
                     </iq>`;
 
                 let response;