Fixed crashing on empty string for UIRichTextLabel

src/dawn/scene/components/ui/text/UIRichTextLabel.cpp

@@ -30,6 +30,7 @@ void UIRichTextLabel::onStart() {
 
     std::function<void(Xml*)> parseChildren = [&](Xml *node) {
       if(node->children.empty()) {
+        if(node->node == "root") return;
         struct UILabelText text;
         text.style = current;
         text.text = node->value;