Escaping attribute at walker class.

As the data are coming from WordPress background, escaping attributes aren't that necessary. But I think best practice what ever or where ever the data is coming form that should be escaped and validated before storing and presenting. So escaping the attributes are better here.

walker.taxonomy-single-term.php

@@ -81,9 +81,9 @@ public function start_el( &$output, $term, $depth = 0, $args = array(), $id = 0
 		$in_selected   = in_array( $term->term_id, $selected_cats );
 
 		$args = array(
-			'id'            => $taxonomy .'-'. $term->term_id,
-			'name'          => $name,
-			'value'         => $value,
+			'id'            => esc_attr( $taxonomy .'-'. $term->term_id ),
+			'name'          => esc_attr( $name ),
+			'value'         => esc_attr( $value ),
 			'checked'       => checked( $in_selected, true, false ),
 			'selected'      => selected( $in_selected, true, false ),
 			'disabled'      => disabled( empty( $args['disabled'] ), false, false ),