bug#25825: 25.1; ispell-find-hunspell-dictionaries not working on Windows

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> It's OK, but wouldn't it be more helpful if we added something like
>
>   (is $LANG unset?)
>
> to the error message text?

I actually had that at first but removed it for brevity.

But I guess it's worth being more helpful in this exceptional
circumstance, so I'll add it back in.  Thanks.