fixed error
  An exception of category 'FatalRootError' occurred while
  [0] Processing run: 1 lumi: 7 event: 601
  [1] Running path 'Candidates'
  [2] Calling event method for module SVfitInterface/'SVllCand'
  Additional Info:
     [a] Fatal Root Error: @SUB=GSLError
  Error 4 in vegas.c at 125 : xu must be greater than xl
reported by Luca