In some cases property allLabels is undefined

[marten-cz]

We found this issue when using amcharts-react. The problem is in this method when the a would be undefined

    redrawLabels: function() {
        this.labels = [];
        var a = this.allLabels;
        this.createLabelsSet();
        var b;
        for (b = 0; b < a.length; b++)
            this.drawLabel(a[b])
    },

Fix like this will solve the issue

var a = this.allLabels || [];