Fix invalid deref in NativeScript script classes

modules/gdnative/nativescript/nativescript.cpp

@@ -1585,12 +1585,16 @@ bool NativeScriptLanguage::handles_global_class_type(const String &p_type) const
 String NativeScriptLanguage::get_global_class_name(const String &p_path, String *r_base_type, String *r_icon_path) const {
 	Ref<NativeScript> script = ResourceLoader::load(p_path, "NativeScript");
 	if (script.is_valid()) {
-		*r_base_type = script->get_instance_base_type();
-		*r_icon_path = script->get_script_class_icon_path();
+		if (r_base_type)
+			*r_base_type = script->get_instance_base_type();
+		if (r_icon_path)
+			*r_icon_path = script->get_script_class_icon_path();
 		return script->get_script_class_name();
 	}
-	*r_base_type = String();
-	*r_icon_path = String();
+	if (r_base_type)
+		*r_base_type = String();
+	if (r_icon_path)
+		*r_icon_path = String();
 	return String();
 }