- Call schannel_shutdown if the SSL connection fails.
Prior to this change schannel_shutdown (which shuts down the SSL
connection as well as memory cleanup) was not called when the SSL
connection failed (eg due to failed handshake).
Co-authored-by: Gisle Vanem
Fixes https://github.com/curl/curl/issues/7877
Closes https://github.com/curl/curl/pull/7878