UFO energy per layer fix

This MR fixes an occasional segfault produced by !56971 (merged) which caused certain ART tests to fail, by making sure that otherObject() exists before checking its type. Marking as urgent because this is needed for JETM1.

I have now tested on more events to make sure that I do not run into any issues.

Tagging @mleblanc @mswiatlo @camacho @cdelitzs @haweber @mspalla

Reconstruction/Jet/JetMomentTools/Root/JetCaloEnergies.cxx

@@ -209,7 +209,7 @@ void JetCaloEnergies::fillEperSamplingFE(const xAOD::Jet& jet, std::vector<float
 
     for (size_t n = 0; n < constit->otherObjects().size(); ++n) {
       if(! constit->otherObject(n)) continue;
-     int index_pfo = constit->otherObject(n)->index();
+      int index_pfo = constit->otherObject(n)->index();
   	  if(index_pfo<0) continue;
 
       const auto* fe = (constit->otherObject(n));
@@ -222,7 +222,7 @@ void JetCaloEnergies::fillEperSamplingFE(const xAOD::Jet& jet, std::vector<float
       //If we have a PFO, we should still get the associated cluster first
       else {
         const xAOD::FlowElement* pfo = dynamic_cast<const xAOD::FlowElement*>(fe);
-        if(pfo->otherObjects().size() > 0 && pfo->otherObject(0)->type() == xAOD::Type::CaloCluster){
+        if(pfo->otherObjects().size() > 0 && pfo->otherObject(0) && pfo->otherObject(0)->type() == xAOD::Type::CaloCluster){
           cluster = dynamic_cast<const xAOD::CaloCluster*> (pfo->otherObject(0));
         }
       }