折线图有空数据时，图例点击失效，设置 connectNulls: true 也没用 #4235

当折线图有空数据，且图表关闭了动画，即设置 chart.animate(false)，图例点击失效，设置 connectNulls: true 将空数据连起来也没用，我并不想把空数据剔除，这些空数据在我的场景也有意义。在官网复现了问题，代码如下：

import { Chart } from '@antv/g2';

const data = [
  { month: 'Jan', city: 'Tokyo', temperature: 7 },
  { month: 'Jan', city: 'London', temperature: 3.9 },
  { month: 'Feb', city: 'Tokyo', temperature: null },
  { month: 'Feb', city: 'London', temperature: 4.2 },
  { month: 'Mar', city: 'Tokyo', temperature: 9.5 },
  { month: 'Mar', city: 'London', temperature: null },
  { month: 'Apr', city: 'Tokyo', temperature: 14.5 },
  { month: 'Apr', city: 'London', temperature: 8.5 },
  { month: 'May', city: 'Tokyo', temperature: 18.4 },
  { month: 'May', city: 'London', temperature: 11.9 },
  { month: 'Jun', city: 'Tokyo', temperature: 21.5 },
  { month: 'Jun', city: 'London', temperature: 15.2 },
  { month: 'Jul', city: 'Tokyo', temperature: 25.2 },
  { month: 'Jul', city: 'London', temperature: 17 },
  { month: 'Aug', city: 'Tokyo', temperature: 26.5 },
  { month: 'Aug', city: 'London', temperature: 16.6 },
  { month: 'Sep', city: 'Tokyo', temperature: 23.3 },
  { month: 'Sep', city: 'London', temperature: 14.2 },
  { month: 'Oct', city: 'Tokyo', temperature: 18.3 },
  { month: 'Oct', city: 'London', temperature: 10.3 },
  { month: 'Nov', city: 'Tokyo', temperature: 13.9 },
  { month: 'Nov', city: 'London', temperature: 6.6 },
  { month: 'Dec', city: 'Tokyo', temperature: 9.6 },
  { month: 'Dec', city: 'London', temperature: 4.8 },
];

const chart = new Chart({
  container: 'container',
  autoFit: true,
  height: 500,
});

chart.data(data);
chart.scale({
  month: {
    range: [0, 1],
  },
  temperature: {
    nice: true,
  },
});

chart.tooltip({
  showCrosshairs: true,
  shared: true,
});

chart.axis('temperature', {
  label: {
    formatter: (val) => {
      return val + ' °C';
    },
  },
});

chart
  .line({ connectNulls: true })
  .position('month*temperature')
  .color('city')
  .shape('smooth');

chart
  .point()
  .position('month*temperature')
  .color('city')
  .shape('circle');

chart.animate(false);

chart.render();