UI: iOS: disable list rows when no config

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Sources/WireGuardApp/UI/iOS/ViewController/TunnelsListTableViewController.swift

@@ -344,6 +344,7 @@ extension TunnelsListTableViewController: UITableViewDelegate {
         }
         guard let tunnelsManager = tunnelsManager else { return }
         let tunnel = tunnelsManager.tunnel(at: indexPath.row)
+        guard tunnel.tunnelConfiguration != nil else { return }
         showTunnelDetail(for: tunnel, animated: true)
     }