FDL-3530🐞 fix:custom_tree的expander支持virtual_group

src/base/tree/customtree.js

@@ -51,6 +51,7 @@ BI.CustomTree = BI.inherit(BI.Widget, {
                 }, BI.deepClone(o.expander), {
                     id: node.id,
                     pId: node.pId,
+                    key: node.key,
                 });
                 var el = BI.stripEL(node);
                 if (!BI.isWidget(el)) {