Set number of events to 1000 for IDEA_o2 example

To monitor the event rate 1000 events are needed to get stable results.
With this example we have around 0.8-1.0 s/evt for 10 GeV e- showeing in the
endcap calorimeter.

example/SteeringFile_IDEA_o2_v01.py

@@ -16,7 +16,7 @@
 ## Macro file to execute for runType 'run' or 'vis'
 SIM.macroFile = ""
 ## number of events to simulate, used in batch mode
-SIM.numberOfEvents = 10
+SIM.numberOfEvents = 1000
 ## Outputfile from the simulation: .slcio, edm4hep.root and .root output files are supported
 SIM.outputFile = "IDEA_o2_v01.root"
 ## Physics list to use in simulation