Join the lobby with two 0ad instances and a moderator account, have one of the players kicked, open the lobby dialog.
Consider whether it is cleaner to always define the property or whether it is cleaner to use the `!!msg.historic` cheat in JS.
The freezing can be tested by modifying the msg in lobby.js if historic = true, e.g.
```
"room-message": msg => {
if (msg.historic)
msg.elexis = "stupid";
```