URLs in documentation: Autoconf Macro Archive

[Ralf Wildenhues]

The URL to the Autoconf Macro Archive (cited in autoconf.texi)
  http://www.gnu.org/software/ac-archive/

works (and redirects to http://autoconf-archive.cryp.to/ ), but there is
a glitch:
  http://www.gnu.org/software/ac-archive

does not redirect, but instead gives an unhelpful 404.  GUI helpers such
as the GNOME context menu may omit the final slash from the URL when
grabbing it from a terminal, thus the user may assume a dead link.

Can this be fixed at the web server or should autoconf.texi maybe use
the redirected-to URL?

(All other URLs in the texi files work, BTW.)

Cheers,
Ralf