Update G4 Commands for Cerenkov photons

As reported in #2913, G4 Commands for Cerenkov photons were defunct
with current FS G4 version.

sim/transport/steer/CbmGeant4Settings.h

@@ -97,10 +97,15 @@ public:
 private:
   std::array<std::string, 3> fG4RunConfig {{"geomRoot", "QGSP_BERT_EMV+optical", "stepLimiter"}};
 
+  /*
+  See https://redmine.cbm.gsi.de/issues/2913
+  As of Geant4-10.5 these commands were changed.
+  Tested for Geant4-11
+  */
   std::vector<std::string> fG4Commands {"/process/optical/verbose 0",
-                                        "/process/optical/defaults/cerenkov/setMaxPhotons 20",
-                                        "/process/optical/defaults/cerenkov/setMaxBetaChange 0.1",
-                                        "/process/optical/setTrackSecondariesFirst Cerenkov true",
+                                        "/process/optical/cerenkov/setMaxPhotons 20",
+                                        "/process/optical/cerenkov/setMaxBetaChange 0.1",
+                                        "/process/optical/cerenkov/setTrackSecondariesFirst true",
                                         "/process/optical/processActivation Cerenkov true",
                                         "/process/optical/processActivation OpAbsorption true",
                                         "/process/optical/processActivation OpBoundary true"};