Fix 2023-e positron run VETO

Plot below shows a comparison for VETO central cell for a MIP-like particle in ECAL with full energy deposition in HCAL (different statistics)

Clearly, the data is at smaller energy than MC. My explanation for this: at 70 GeV, the average light intensity seen by the PMTs coupled to VETO is smaller, hence the gain is smaller (well-known effect in NA64).

This should be corrected for!