message: Add protection for Nanos when the PID response is available
diff: @@ -344,7 +344,7 @@ bool AliSigma0PhotonCuts::ProcessPhoton(AliVEvent* event, AliMCEvent *mcEvent,
  float pidPos = -999.f;
  float pidNeg = -999.f;
  - if (fPIDResponse) {
  + if (fPIDResponse && !(nanoPos && nanoNeg)) {
  pidPos = fPIDResponse->NumberOfSigmasTPC(pos, AliPID::kElectron);
  pidNeg = fPIDResponse->NumberOfSigmasTPC(neg, AliPID::kElectron);
  } else if(nanoPos && nanoNeg) {
  