Several adjustments to sentence explaining users involvement in TLS1.2
Turn 'of' to 'when' and correct spelling on certificate.
The sentence being referenced starts on this line: https://gitlab.com/gemini-specification/protocol/-/blob/master/specification.gmi#L137
Maybe the wording was meant to be something closer to, "A client MAY warn a user when a TLS 1.2 connection is established, and SHOULD warn the user when a client certificate will be transmitted via TLS 1.2."