Add workaround for broken TLS SNI in Windows 8.1 for the archive updater

Asking users to download update (manifests) via an insecure connection is not
ideal, but considering most of them downloaded the original test build via an
insecure connection in the first place it might be ok

Unfortunately the detection is not perfect, so genuine TLS attacks can be
misinterpreted as the bug; completely invalid/expired/otherwise broken
certificates should be rejected though