[patch] add forgotten documentation bits for issuer altname

[Simon Josefsson]

Brad Hards <bradh at frogmouth.net> writes:

> Hi,
>
> While poking around the documentation, I realised that I had forgotten
> part of the documentation - the "since" part that generates the "new
> in 2.10.0" index.
>
> Patch attached. I tested this by re-generating the documentation and
> making sure it appears in the html output.

Thanks, pushed.

/Simon