message: Fix chat scrollback loading the same messages
diff: @@ -480,7 +480,7 @@ export function loadOlderChatMessages(chat: ChatClient, roomId: number) {
  const firstMessage = chat.messages[roomId][0];
  chat.roomChannels[roomId]
  - .push('load_messages', { before_id: firstMessage.id })
  + .push('load_messages', { before_date: firstMessage.logged_on })
  .receive('ok', onLoadMessages)
  .receive('error', onLoadFailed)
  .receive('timeout', onLoadFailed);
  