Allow ARIA instructions to be overwritten by an empty string

Author: aimeos

packages/he-tree-vue/src/components/DraggableTree.ts

@@ -493,7 +493,7 @@ const cpt = defineComponent({
     };
     // Accessibility: keyboard instructions
     this.ariaInstructions =
-      this.i18n?.instructions ||
+      this.i18n?.instructions ??
       "Use arrow keys to navigate. Alt plus arrow keys to reorder.";
 
     this.treeDraggableInstance = extendedDND(rootEl, {