fix wild pointers caused by vector expansion

src/CraneCtld/TaskScheduler.cpp

@@ -2008,6 +2008,7 @@ bool MinLoadFirst::CalculateRunningNodesAndStartTime_(
         return lhs->it->first > rhs->it->first;
       });
 
+  trackers.reserve(craned_indexes_.size());
   for (CranedId craned_id : craned_indexes_) {
     auto& time_delta_res_map =
         node_selection_info.node_time_delta_res_map.at(craned_id);