Adjlist->delete_edge not working with is_directed=false

[ht-gong]

Code to reproduce error:

#pragma omp parallel for
    for (int i = 0; i < THREAD_NUM; i++)
    {
        GraphBase* graph = myEngine.create_graph_handle();
        int ret = -1;
        if (i % 2 == 0)
        {
            graph->add_node(node{.id = i + 100});
            // graph->add_edge(edge{.src_id = i, .dst_id = 1}, false);
        }
        else
        {
            while (ret != 0)
            {
                ret = graph->add_edge(edge{.src_id = 1, .dst_id = i - 1 + 100},
                                      false);
            }
        }
        graph->close();
    }

#pragma omp parallel for
    for (int i = 0; i < THREAD_NUM; i++)
    {
        GraphBase* graph = myEngine.create_graph_handle();
        int ret = -1;
        if (i % 2 == 0)
        {
        }
        else
        {
            while (ret != 0)
            {
                ret = graph->delete_edge(1, i - 1 + 100);
            }
        }
        graph->close();
    }

After running the segement, in/out_degree on nodes becomes a large number (probably because the degrees got reduced into the negative range)