Fix event selection for not-anchored simulations

@ekryshen 
the introduction of the mapRCT breaks not-anchored simulation, where the default runNumber is set to 300000 and the map is not filled. Does this fix make sense? I tested it locally and it works

Author: fmazzasc

Common/TableProducer/eventSelection.cxx

@@ -262,7 +262,7 @@ struct BcSelectionTask {
 
     int run = bcs.iteratorAt(0).runNumber();
 
-    if (run != lastRun && run >= 500000) {
+    if (run != lastRun && run >= 300000) {
       lastRun = run;
       auto runInfo = o2::parameters::AggregatedRunInfo::buildAggregatedRunInfo(o2::ccdb::BasicCCDBManager::instance(), run);
       // first bc of the first orbit