Registrer connected players correctly

The issue with multiple local players on one client was likely due to
the connectedPlayers list not being populated with those extra players,
making the server think it needed to spawn a disconnected player for
them. Whoops.

Assets/Scripts/Control&Input/Peer2PeerTransport.cs

@@ -360,11 +360,13 @@ private void OnSpawnPlayerInput(NetworkConnectionToClient connection, PlayerConn
         {
             isConnectionAlreadyPresent = false;
             connections.Add(connection);
-            connectedPlayers.Add((uint)playerIndex);
         }
+
+        // Register player
         if (!playersForConnection.ContainsKey(connection.connectionId))
             playersForConnection[connection.connectionId] = new();
         playersForConnection[connection.connectionId].Add((uint)playerIndex);
+        connectedPlayers.Add((uint)playerIndex);
 
         // Determine metadata
         var playerType = PlayerType.Local;