prosody: tune internal muc settings

* prosody: tune internal muc settings

prosody/rootfs/defaults/conf.d/jitsi-meet.cfg.lua

@@ -312,8 +312,10 @@ Component "{{ $XMPP_INTERNAL_MUC_DOMAIN }}" "muc"
         {{ end -}}
     }
     restrict_room_creation = true
+    muc_filter_whitelist="{{ $XMPP_AUTH_DOMAIN }}"
     muc_room_locking = false
     muc_room_default_public_jids = true
+    muc_room_cache_size = 1000
 
 Component "{{ $XMPP_MUC_DOMAIN }}" "muc"
     restrict_room_creation = true