Accept connection failure on Windows in ssl_alert_reporting.js

Windows sometimes observes connection failures instead of TLS alert packets in ssl_alert_reporting.js. This is because the server writes the packet, then issues a shutdown with SD_BOTH. Because there is data in the receive queue, this causes the server to emit an RST packet. This can pre-empt the client's handling of the written packet.

On Windows, we should retry the test, if we encounter a connection failure.