Bug#126208: boot-floppies: First choose DHCP-Configure, then change to static

[pb@nexus.co.uk]

In message <[🔎] 20011222212713.GA6719@hermes.kutzsche.net>, Immanuel Scholz writes:
>When first choose DHCP (with working Server nearby), then change (rechoosing 
>"Configure Network") to some static IP, the installer seems to remind the
>old IP and reset it after a while (about 2-3 Minutes, I think depents on the
>TTL of the IP).

Looks like configure_static_network() needs to take steps to kill off the
DHCP daemons (pump and/or dhclient) if they're running.

p.