plugin XEP-0433: Check frontend's allow_external option:

To allow external search, there must now be both the general settings and the
`allow_external` option set by frontend.

libervia/backend/plugins/plugin_xep_0433.py

@@ -292,7 +292,7 @@ class XEP_0433:
         sequence_matcher: difflib.SequenceMatcher,
         matches: plugin_misc_jid_search.SearchItems,
     ) -> bool:
-        if options.groupchat and self.allow_external:
+        if options.groupchat and self.allow_external and options.allow_external:
             log.debug(f"Search {search_term!r} at {self.group_chat_search_default_jid}.")
             try:
                 external_items = await self.search(