silence warning in category with isset check
silence warning in category with isset check

martybel/wordpress-fantastic-elasticsearch,innovatordm/wordpress-fantastic-elasticsearch,parisholley/wordpress-fantastic-elasticsearch,martybel/wordpress-fantastic-elasticsearch,makeandship/wordpress-fantastic-elasticsearch,parisholley/wordpress-fantastic-elasticsearch,innovatordm/wordpress-fantastic-elasticsearch,makeandship/wordpress-fantastic-elasticsearch,martybel/wordpress-fantastic-elasticsearch,makeandship/wordpress-fantastic-elasticsearch,innovatordm/wordpress-fantastic-elasticsearch,parisholley/wordpress-fantastic-elasticsearch