Revert EvtGen to old decay file to avoid rare crash

Note: I'm not sure what to do about check_modified_files failing.

Description of bug

Low filter pass rate meant that a very rare problem in the new EvtGen decay tables was triggered (see discussion on ATLMCPROD-10179)

Changes introduced

As suggested by @mshapiro, I've added

evgenConfig.auxfiles += ['2014Inclusive_17.dec']
decayfile_str = "2014Inclusive_17.dec"
genSeq.EvtInclusiveDecay.decayFile = decayfile_str

to the job options to revert to the old EvtGen decay tables.

Tests

Tested here: https://bigpanda.cern.ch/jobs/?jeditaskid=30762034