Fix tst_QWebSocket::tst_invalidOpen for catch-all DNS setups.

Instead of relying on a hostname which might still be resolved in
some DNS setups (i.e. always forward to google search or intranet),
we now try to connect to localhost port 1 which should yield a
ConnectionRefusedError.

This way, the test passes for me on my setup.

Change-Id: I025824796e94e718a42c4999706f647a72b37659
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>