fix evaluation for optDepth

packages/plugin-lsx/src/components/LsxPageList/LsxPage.jsx

@@ -33,7 +33,7 @@ export class LsxPage extends React.Component {
 
     // process depth option
     const optDepth = this.props.lsxContext.getOptDepth();
-    if (optDepth === undefined) {
+    if (optDepth == null) {
       this.setState({ isLinkable: true });
     }
     else {