After some research into this error, I believe you will have to contact your webhost in order to correct this. According to WordPress support (this is a server level error, not a WP or even Connections level error):
“What is happening here is that your site is trying to connect to Connections server but failing because the connection method your server is using is too old.
What needs to be updated is curl and OpenSSL. This should be updated not only for the functionality of Connections and your SSL connections, but for the security of your site in general as well.
If you are not hosting the site yourself you will need to reach out to your host and ask them to update curl.”
Hope this helps, let me know.