Bug#757116: cloud-scripts: Stop the build when 0 node available

[Sylvestre Ledru <sylvestre@debian.org>]

Package: qa.debian.org
Severity: minor

Hello,

Starting a build with 0 node should stop the builds.

Instead, I get:
[00:01] Starting 868 tasks on 0 nodes (3 slots per node) ...
[00:02] *** total: 868 OK: 0 (0%) To retry: 0 (0%) Failed: 0 (0%)

Etc

Thanks,
Sylvestre

-- System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (900, 'testing'), (600, 'unstable'), (500, 'stable-updates'), (500, 'stable'), (300, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.13-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash