Bug#649888: Hide /icons index

[Stefan Fritsch <sf@sfritsch.de>]

On Thursday 24 November 2011, Mathieu Parent wrote:
> Currently, on any Debian-based apache2, anyone can browse the
> /icons URL.
> 
> Anyone can see that odf6* icons are present (-> this is Debian
> specific) and the date of these icons correspond to the build date.
> 
> So one can deduce the version and arch (for example "29-Sep-2011
> 23:00" is apache2 2.2.16-6+squeeze4 amd64)

Not leaking the arch is certainly a valid request.

> Recommendation: remove the "Indexes" option in
> 'config-dir/mods-available/alias.conf' [1].

But disabling the Index page is not enough. The server sends the date 
of the icons in the Last-Modified header. Setting the icon dates 
during build time should work, though.