fix job splitting for ACDC MCFakeFile

This commit should fix two things (do NOT merge yet):
 a) when creating production jobs out of ACDC documents ( for MCFakeFile), do not use the fileset/lfn number of events (it corresponds to 250 jobs actually). Instead, create a job to recover only those missing lumis.
 b) take into account changes applied to the job splitting (EventBased) set for the new ACDC workflow -> TO BE FIXED
Yes, because "acdcFile["events']" is the total number of events to be processed in one fileset (one MCFakeFile, which is splitted among 250 jobs).
For the workflow we were investigating, this was around 3M events. That's why we look at the number of lumis for that specific job/document.