Requested by Greg -- upon a new release, the queue and baseline repos
are changed at similar time by a script. Given the scripting and repo
mirroring, this is not atomic and there's a chance that we trigger
testing with a not-yet modified queue and baseline with already applied
patches.

To avoid this situation, check the date of the commits we want to
trigger with. If any of them were changed less than X minutes ago,
abort. While this means we may trigger real queue changes a few minutes
later than before, we need to wait for potential baseline update.

Signed-off-by: Veronika Kabatova <vkabatov@redhat.com>