Override remain at station behaviour for road vehicles with explicit stop direction set

(cherry picked from commit 8f8d635baf3dc1506de206a3378498bedfd020bf)

See: #686

src/roadveh_cmd.cpp

@@ -1609,6 +1609,7 @@ static bool CheckRestartLoadingAtRoadStop(RoadVehicle *v)
 	const Order *next_order = v->GetOrder(next_order_idx);
 	FlushAdvanceOrderIndexDeferred(v, false);
 	if (next_order != nullptr && next_order->IsType(OT_GOTO_STATION) && next_order->GetDestination() == station_id &&
+			(next_order->GetRoadVehTravelDirection() == INVALID_DIAGDIR || next_order->GetRoadVehTravelDirection() == DirToDiagDir(v->direction)) &&
 			!(next_order->GetNonStopType() & ONSF_NO_STOP_AT_DESTINATION_STATION) &&
 			IsInfraTileUsageAllowed(VEH_ROAD, v->owner, v->tile) &&
 			GetRoadStopType(v->tile) == (v->IsBus() ? ROADSTOP_BUS : ROADSTOP_TRUCK)) {