Failed to download kernel

[Göran Lundquist]

The site ftp.all.kernel has shutdown so the barrier_breaker/scripts/download.pl need to be adjusted.

Proposed adjustment:

foreach my $dir (@extra) {
                       push @mirrors, "https://www.kernel.org/pub/$dir";
                       push @mirrors, "ftp://ftp.all.kernel.org/pub/$dir";
                       push @mirrors, "http://ftp.all.kernel.org/pub/$dir";
}

[edwin]

Thanks.