Add protection for empty CSCCluster fit results

In the trigger we can run into the case where we have some empty CSC clusters which is resulting in empty CSCCluster fit results, so adding some protection to avoid accessing these empty fit results. Fixes ATR-22055.

MuonSpectrometer/MuonReconstruction/MuonRIO_OnTrackCreators/MuonClusterOnTrackCreator/src/CscClusterOnTrackCreator.cxx

@@ -330,7 +330,11 @@ namespace Muon {
       std::vector<ICscClusterFitter::Result> results, results0;
       results = m_clusterUtilTool->getRefitCluster(MClus,tantheta);
       results0 = m_clusterUtilTool->getRefitCluster(MClus,0);
-      
+
+      if(&results[0]==nullptr || &results0[0]==nullptr){
+	ATH_MSG_VERBOSE("No fit result");
+	return new CscClusterOnTrack(MClus,locpar,loce,positionAlongStrip,MClus->status(),MClus->timeStatus(),MClus->time());
+      }
       ICscClusterFitter::Result res, res0;
       res = results[0];
       res0 = results0[0]; // result at normal angle to make error blown correctly in case of cosmic