chartkit - dont require charts to define showLegend

ext/chart_kit/ang/crmChartKit/crmSearchDisplayChartKit.component.js

@@ -339,7 +339,7 @@
           this.formatCoordinateGrid();
         }
 
-        if (this.chartType.showLegend(this)) {
+        if (this.chartType.showLegend && this.chartType.showLegend(this)) {
           this.addLegend();
         }
       };