[CI] Make sure we are on correct branch before running script

In commit db7320bd, I tried to optimize things by move the 'git checkout origin/os-build' to the common setup section. The side affect of this move meant that the last git checkout branch went from os-build to ark-infra. Therefore the ark-create-release.sh script was always outdated.

I can fix this by reverting that change and adding the checkout os-build line to every variant of the future cronjobs or just add it to the one place that needs it, rawhide_release. So I am choosing to add it once.

Fixes: #123 (closed)

Signed-off-by: Don Zickus dzickus@redhat.com