feat: add optgroup label support in feed options sanitizer (#1101)

Author: RaduCristianPopescu

includes/feedzy-rss-feeds-feed-tweaks.php

@@ -445,6 +445,10 @@ function ( $allowed_html = array() ) {
 				'class'    => array(),
 				'selected' => array(),
 			),
+			'optgroup' => array(
+				'label'    => array(),
+				'disabled' => array(),
+			),
 			'input'    => array(
 				'type'        => array(),
 				'id'          => array(),