fix: correct writing of accessTransitStopId, ref #316 (#317)

Author: Hussein-Mahfouz

core/src/main/java/org/eqasim/core/simulation/modes/feeder_drt/analysis/passengers/FeederTripSequenceWriter.java

@@ -65,8 +65,8 @@ public void writeTripItems(File path) throws IOException {
                     Double.isNaN(item.accessArrivalTime) ? "NaN" : String.valueOf(item.accessArrivalTime),
                     Double.isNaN(item.egressArrivalTime) ? "NaN" : String.valueOf(item.egressArrivalTime),
 
-                    String.valueOf(item.accessVehicleId),
-                    String.valueOf(item.egressVehicleId),
+                    String.valueOf(item.accessTransitStopId),
+                    String.valueOf(item.egressTransitStopId),
 
                     String.valueOf(item.accessTransitLineId),
                     String.valueOf(item.egressTransitLineId),