Reload key with more 'strict' options without password

[Damien Miller]

On Fri, 31 Aug 2012, n3rd at Safe-mail.net wrote:

> Excuse me for lame question..
>
> Imagine you load some private key with ssh-add with no options, so it
> could be used forever. And after some time you decide to reload it
> with more 'restrictive' options, like '-t' or '-c'. Why ask password
> again? If it's the same key (with the same fingerprint)..

There is no ssh-agent protocol message to express "update this already-
loaded key's contraints only".

-d