example-preseed.txt: please use CIDR notation isntead of netmask

[Ansgar <ansgar@debian.org>]

Hi,

example-preseed.txt[1] contains the following:

+---
| #d-i netcfg/get_ipaddress string 192.168.1.42
| #d-i netcfg/get_netmask string 255.255.255.0
| [...]
| #d-i netcfg/get_ipaddress string fc00::2
| #d-i netcfg/get_netmask string ffff:ffff:ffff:ffff::
+---

At least in the interactive mode of the installer one can instead
specify the address as 192.168.1.42/24 or fc00::2/64 instead and won't
get asked about the netmask.

I think the example should use this notation instead, especially for
non-legacy IP. (I've not verified it works with preseeding though.)

I've not found where example-preseed.txt comes from; a quick grep
through webwml.git did not find it. So I just write to this list :-)

Ansgar

  [1]: https://www.debian.org/releases/stable/example-preseed.txt