This reverts commit 1b457a5d.
It wasn't prudent to switch everyone to master FTP server;
Yandex mirror still has an order of magnitude more bandwidth.

%_host_cpu was a wrong choice in the first place,
and the particular case of %_arch == ppc64le
with %_host_cpu == powerpc64le became the culprit.

Yandex mirror can lag behind at times:
http://mirmon.altlinux.org/sisyphus.html#ru

...and we've got 1GbE there now, not that bad
compared to 100Mbps back then...

NB: yandex traffic might be billed as "local"
    in many regions, this should be revisited.

...instead of (often-crowded) ftp.altlinux.org for updates.

Old format:
rpm [p7] http://ftp.altlinux.org/pub/distributions/ALTLinux/p7/branch x86_64 classic
New format:
rpm [p8] http://ftp.altlinux.org/pub/distributions/ALTLinux p8/branch/x86_64 classic

This is about (a)synchronous package builder in fact.

See http://www.opennet.ru/openforum/vsluhforumID3/86239.html#1
for a query that has led to this one; in particular,
- xdm dropped (won't log in root and there are no users yet);
- network is brought up and configured via DHCP by default;
- apt-get works out-of-box;
- default image size is twice the chroot size.