client: Fix switching notes, default text

src/public/app/widgets/type_widgets/mind_map.js

@@ -33,16 +33,12 @@ export default class MindMapWidget extends TypeWidget {
                     el: this.$content[0],
                     direction: MindElixir.LEFT
                 });
-                mind.init(MindElixir.new("hello"));
+                mind.init(MindElixir.new());
             });
 
         super.doRender();
     }
 
-    cleanup() {
-        this.$widget.empty();
-    }
-
     async entitiesReloadedEvent({loadResults}) {
         if (loadResults.isNoteReloaded(this.noteId)) {
             this.refresh();