bug#68799: 30.0.50; emacs --fg-daemon fails silently if server-start fails

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: 68799@debbugs.gnu.org
> Date: Mon, 29 Jan 2024 13:13:42 -0500
> 
> --- a/lisp/startup.el
> +++ b/lisp/startup.el
> @@ -1627,7 +1627,11 @@ command-line
>    (let ((dn (daemonp)))
>      (when dn
>        (when (stringp dn) (setq server-name dn))
> -      (server-start)
> +      (condition-case err
> +          (server-start)
> +        (error
> +         (message "%s" (error-message-string err))
> +         (kill-emacs 1)))

Thanks, this needs a comment explaining why we need condition-case and
where does error-message-string come from.