The "needs to have a value for field" messages are incorrect and
reference nonexistent fields since the commit in which they were
introduced (refs #18823).

starttls(), login(), and other connection methods already call
the method as needed.

Thanks Adam Chainz for review and guidance.

Thanks Jaap Roes for the initial patch.

These values are duplicated in the super().

Regression in 374e6230.

Thanks Florian Apolloner for the report and analysis.

Unused (always True) after 3e43d24a.

Thanks Anton Gilgur for the report and review.