message: Fix trigger class selection
diff: @@ -82,7 +82,7 @@ AliEventCuts::AliEventCuts(bool saveplots) : TList(),
  fVZEROvsTPCoutPolCut{1.e8,0.,0.,0.,0.},
  fRequireExactTriggerMask{false},
  fTriggerMask{AliVEvent::kAny},
  - fTriggerClasses{""},
  + fTriggerClasses{},
  fContainer{},
  fkLabels{"raw","selected"},
  fManualMode{false},
  @@ -160,7 +160,7 @@ bool AliEventCuts::AcceptEvent(AliVEvent *ev) {
  /// A special bit is set in this case
  TString classes = ev->GetFiredTriggerClasses();
  for (const std::string& myClass : fTriggerClasses) {
  - if (classes.Contains(myClass.data())) {
  + if (classes.Contains(myClass.data()) && !myClass.empty()) {
  fFlag |= BIT(kTrigger);
  fFlag |= BIT(kTriggerClasses);
  break;
  