The comment in QNativeSocketEnginePrivate::fetchConnectionParameters()
talked about IPv6 v4-mapped addresses. However, toIPv4Address also
converts the unspecified address (::), which resulted in QAbstractSocket
saying that it had bound to QHostAddress::Any instead of
QHostAddress::AnyV6
Change-Id: I572733186b73423b89e5fffd15f138579c5c0c50
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>