CI: periodic jobs fail during testenv-client invocation

[Gabriele Cerami]

logs at

http://logs.openstack.org/periodic/periodic-tripleo-ci-centos-7-ovb-updates/b4b3d55/console.html#_2017-02-10_06_29_07_473783

show error

2017-02-10 06:29:07.473783 | Traceback (most recent call last):
2017-02-10 06:29:07.473930 | File "./testenv-client", line 219, in <module>
2017-02-10 06:29:07.474104 | exit(main())
2017-02-10 06:29:07.474263 | File "./testenv-client", line 183, in main
2017-02-10 06:29:07.474423 | job_identifier = '%s: %s' % (os.environ['ZUUL_CHANGE'],
2017-02-10 06:29:07.474539 | File "/usr/lib64/python2.7/UserDict.py", line 23, in __getitem__
2017-02-10 06:29:07.474691 | raise KeyError(key)
2017-02-10 06:29:07.474822 | KeyError: 'ZUUL_CHANGE'

Change I848e08cd272724c059ce92a6ee527dedcd53acce introduced a new job identifier that is formed by env variables ZUUL_CHANGE and TOCI_JOBTYPE, but does not offer a default if they are missing.

On periodic jobs ZUUL_CHANGE is not set, so the invocation of testenv-client always fails

[Gabriele Cerami (gcerami)]

proposed https://review.openstack.org/432278 to fix