Unset a given SendEnv?

[Damien Miller]

On Tue, 3 Jul 2018, Martin Drescher wrote:

> G'day openssh-unix-dev,
> 
> is there a way to unset a 'SendEnv' given by /etc/ssh/ssh_config?

HEAD has the ability to clear one using SendEnv=-FOO, but I'm toying
with the idea of breaking backwards compatibility and making SendEnv
behave like the rest of the options and be first match wins.

What do you all think?

-d