[Chartjs]-Chart js vertical line z-index

var ctx = document.getElementById('chart').getContext("2d");
var gradientStroke = ctx.createLinearGradient(1000, 1000, 1000, 0);

gradientStroke.addColorStop(1, "rgb(33, 240, 43)");
gradientStroke.addColorStop(0.25, "rgb(21, 168, 226)");
gradientStroke.addColorStop(0.5, "rgb(21, 168, 226)");
gradientStroke.addColorStop(0, "rgb(14, 144, 177)");


var data = {
  legend: false,
  labels: ["02 FEB", "03 FEB", "04 FEB", "05 FEB", "06 FEB", "07 FEB", "08 FEB", "09 FEB", "10 FEB", "11 FEB", "12 FEB"],
  datasets: [{
    fill: false,
    backgroundColor: gradientStroke,
    borderColor: gradientStroke,
    borderWidth: 4,
    data: [9412, 17000, 18000, 11000, 9254, 7200, 11600, 15644, 11222, 13333, 12545],
    pointBorderWidth: 9,
    pointRadius: 9,
    pointBorderColor: 'transparent',
    pointHoverRadius: 8,
    pointHoverBorderWidth: 3,
    pointHoverBackgroundColor: '#27f327',
    pointHoverBorderColor: 'white',
    pointBackgroundColor: 'transparent'


  }]
};
var options = {
  hover: {
    mode: 'index',
    intersect: true
  },
  tooltips: {
    backgroundColor: '#FFF',
    bodyFontColor: '#393f5b',
    bodyFontSize: 20,
    displayColors: false,
    bodySpacing: 10,
    intersect: false,
    bodyFontStyle: 'bold',
    xPadding: 15,
    yPadding: 15,
    mode: 'index',
    callbacks: {
      title: function() {}
    }
  },
  legend: {
    display: false
  },
  maintainAspectRatio: false,
  scales: {
    yAxes: [{
      stacked: true,
      gridLines: {
        display: true,
        color: "#6e6e6e26",
        padding: 0,
      },
      ticks: {
        beginAtZero: true,
        min: 0,
        max: 20000,
        stepSize: 5000,
        display: false
      }
    }],
    xAxes: [{
      gridLines: {
        display: false,
        color: "#6e6e6e26",

      },
      ticks: {
        fontSize: 14,
        fontColor: '#afb6d4',
      }
    }]
  }
};

let draw = Chart.controllers.line.prototype.draw;
Chart.controllers.line.prototype.draw = function() {
  draw.apply(this, arguments);
  let ctx = this.chart.chart.ctx;
  let _stroke = ctx.stroke;
  ctx.stroke = function() {
    ctx.save();
    ctx.shadowColor = '#4b4b4b8e';
    ctx.shadowBlur = 20;
    ctx.shadowOffsetX = 1;
    ctx.shadowOffsetY = 2;
    _stroke.apply(this, arguments);
    ctx.restore();
  }
};
Chart.defaults.LineWithLine = Chart.defaults.line;
Chart.controllers.LineWithLine = Chart.controllers.line.extend({
  draw: function(ease) {
    if (this.chart.tooltip._active && this.chart.tooltip._active.length) {
      var activePoint = this.chart.tooltip._active[0],
        ctx = this.chart.ctx,
        x = activePoint.tooltipPosition().x,
        topY = this.chart.scales['y-axis-0'].top,
        bottomY = this.chart.scales['y-axis-0'].bottom;

      // draw line
      ctx.save();
      ctx.beginPath();
      ctx.moveTo(x, topY);
      ctx.lineTo(x, bottomY);
      ctx.lineWidth = 2;
      ctx.strokeStyle = '#000';
      ctx.shadowBlur = 1;
      ctx.stroke();
      ctx.restore();
    }
    Chart.controllers.line.prototype.draw.call(this, ease);
  }
});
var chart = new Chart(ctx, {
  type: 'LineWithLine',
  data: data,
  options: options
});

#chart {
  width: 100%;
  height: 100%;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.bundle.min.js"></script>
<canvas id="chart"></canvas>