openstack: default to 9h job timeout
openstack: default to 9h job timeout

Because a few job take more than 6h. Ideally this could be overriden on
a case by case basis.

Signed-off-by: Loic Dachary <b6eae37fc74638590e3f9030895d42446505d41b@dachary.org>

ktdreyer/teuthology,SUSE/teuthology,ktdreyer/teuthology,dmick/teuthology,SUSE/teuthology,dmick/teuthology,ceph/teuthology,ceph/teuthology,dmick/teuthology,SUSE/teuthology