fix: Fixes handling tenant in util and lobby.

doc/debian/jitsi-meet/jitsi-meet.example

     ssl_session_tickets off;
 
     add_header Strict-Transport-Security "max-age=63072000" always;
+    set $prefix "";
 
     ssl_certificate /etc/jitsi/meet/jitsi-meet.example.com.crt;
     ssl_certificate_key /etc/jitsi/meet/jitsi-meet.example.com.key;
 
     # BOSH
     location = /http-bind {
-        proxy_pass       http://localhost:5280/http-bind;
+        proxy_pass http://127.0.0.1:5280/http-bind?prefix=$prefix&$args;
         proxy_set_header X-Forwarded-For $remote_addr;
         proxy_set_header Host $http_host;
     }
         alias /etc/jitsi/meet/jitsi-meet.example.com-config.js;
     }
 
-    # Anything that didn't match above, and isn't a real file, assume it's a room name and redirect to /
-    location ~ ^/([^/?&:'"]+)/(.*)$ {
-        set $subdomain "$1.";
-        set $subdir "$1/";
-        rewrite ^/([^/?&:'"]+)/(.*)$ /$2;
-    }
-
     # BOSH for subdomains
     location ~ ^/([^/?&:'"]+)/http-bind {
         set $subdomain "$1.";
 
         rewrite ^/(.*)$ /xmpp-websocket;
     }
+
+    # Anything that didn't match above, and isn't a real file, assume it's a room name and redirect to /
+    location ~ ^/([^/?&:'"]+)/(.*)$ {
+        set $subdomain "$1.";
+        set $subdir "$1/";
+        rewrite ^/([^/?&:'"]+)/(.*)$ /$2;
+    }
 }

resources/prosody-plugins/mod_muc_lobby_rooms.lua

 local NOTIFY_LOBBY_ACCESS_DENIED = 'LOBBY-ACCESS-DENIED';
 
 local util = module:require "util";
+local get_room_by_name_and_subdomain = util.get_room_by_name_and_subdomain;
 local is_healthcheck_room = util.is_healthcheck_room;
 local presence_check_status = util.presence_check_status;
 
         local session, reply, node = event.origin, event.reply, event.node;
         if node == LOBBY_IDENTITY_TYPE
             and session.jitsi_web_query_room
-            and main_muc_service
             and check_display_name_required then
-            local room = main_muc_service.get_room_from_jid(
-                jid_bare(session.jitsi_web_query_room .. '@' .. main_muc_component_config));
+            local room = get_room_by_name_and_subdomain(session.jitsi_web_query_room, session.jitsi_web_query_prefix);
+
             if room and room._data.lobbyroom then
                 reply:tag('feature', { var = DISPLAY_NAME_REQUIRED_FEATURE }):up();
             end

resources/prosody-plugins/util.lib.lua

 
     -- if there is a subdomain we are in multidomain mode and that subdomain is not our main host
     if subdomain and subdomain ~= "" and subdomain ~= muc_domain_base then
-        room_address = "["..subdomain.."]"..room_address;
+        room_address = jid.join("["..subdomain.."]"..room_name, muc_domain);
     else
         room_address = jid.join(room_name, muc_domain);
     end