Finish game instantly if all players have left

rust/src/game/mod.rs

@@ -813,6 +813,10 @@ impl Game {
                     peer.broadcast_reliable(Package::SetHostPrivileges(player.id(), true));
                     s.signals().on_host_privileges_changed().emit();
                 }
+
+                if s.players.is_empty() && s.game_started {
+                    s.finish_game();
+                }
             }
         });
     }