remove reduced ES hits from Shashlik configuration

One-line fix in the Shashlik customization to get rid of the warning:
> %MSG-e WrongGeometry:   ReducedESRecHitCollectionProducer:reducedEcalRecHitsES@beginRun  10-Nov-2014 17:34:54 CET Run: 1
> could not cast the subdet geometry to preshower geometry