Do not crash JobStatusLite when it cannot get a value from the job dict

Ok, after 30min I succeeded squashing 3 commits :-)

@ticoann, this PR is meant to fix the crashes in JobStatusLite seen in vocms235. For some reason this call
https://github.com/dmwm/WMCore/blob/master/src/python/WMCore/BossAir/Plugins/CondorPlugin.py#L615
sometimes returns 'undefined' and so it crashes the component.

It looks like only the jobAd.get() for 'runningTime' has a bad return from time to time. But to be on the safe side, I've enclosed the other calls in try/except too.

Let me know if you have any comments and/or do not like the logging warning mode. Thanks