bug in rebuild logger ?

[huanglilong]

https://github.com/hku-mars/ikd-Tree/blob/c0e36a16b6e4d557d3783b16911207f6398dd478/ikd-Tree/ikd_Tree.cpp#L302

            if (int(Rebuild_PCL_Storage.size()) > 0){
                BuildTree(&new_root_node, 0, Rebuild_PCL_Storage.size()-1, Rebuild_PCL_Storage);
                // Rebuild has been done. Updates the blocked operations into the new tree
                pthread_mutex_lock(&working_flag_mutex);
                pthread_mutex_lock(&rebuild_logger_mutex_lock);
                int tmp_counter = 0;
                while (!Rebuild_Logger.empty()){
                    Operation = Rebuild_Logger.front();
                    max_queue_size = max(max_queue_size, Rebuild_Logger.size());
                    Rebuild_Logger.pop();
                    pthread_mutex_unlock(&rebuild_logger_mutex_lock);                  
                    pthread_mutex_unlock(&working_flag_mutex);
                    run_operation(&new_root_node, Operation);
                    tmp_counter ++;
                    if (tmp_counter % 10 == 0) usleep(1);
                    pthread_mutex_lock(&working_flag_mutex);
                    pthread_mutex_lock(&rebuild_logger_mutex_lock);               
                } 
                rebuild_flag = false;  // rebuild flag should in here
               pthread_mutex_unlock(&rebuild_logger_mutex_lock);
            }

after fix this issue, this check not need

            if (!Rebuild_Logger.empty()){
                printf("\n\n\n\n\n\n\n\n\n\n\n ERROR!!! \n\n\n\n\n\n\n\n\n");
            }