message: Fix confusing code causing warning with Clang - thanks Marco
diff: @@ -372,7 +372,7 @@ AliBaseMCTrackDensity::ProcessTracks(const AliMCEvent& event,
  static_cast<AliMCParticle*>(event.GetTrack(iTr));
  // Check if this charged and a primary
  - if (!particle->Charge() != 0) continue;
  + if (particle->Charge() == 0) continue;
  Bool_t isPrimary = event.IsPhysicalPrimary(iTr) && iTr < nPrim;
  