折线图区域填充JSON解析bug

kanban-client/app/component/converter.js

@@ -556,7 +556,7 @@ function getBarSeries(fontSize, layout, series, barconfig) {
 
 function getLineSeries(fontSize, series, lineconfig) {
     let s = [],
-    areaStyleCfg = lineconfig.areaStyle;
+    areaStyleCfg = lineconfig.areaStyle || '{}';
 
     areaStyleCfg = JSON.parse(areaStyleCfg);