fix handling of LHE files in input, thanks to Alan https://hypernews.cern.ch/HyperNews/CMS/get/dataopsrequests/5155/1/1/1/1/1.html
Merge pull request #4540 from franzoni/CMSSW_7_2_X_2014-07-06-1400_fixLHE

fix handling of LHE files in input