Role/Capability: Correct the documented accepted types for the `capab…

…ility` argument of `WP_User_Query`.

See #16841, #54729


git-svn-id: https://develop.svn.wordpress.org/trunk@52653 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-user-query.php

@@ -166,7 +166,7 @@ public static function fill_query_vars( $args ) {
 	 *                                                See WP_Meta_Query::__construct for accepted values and default value.
 	 *     @type array           $meta_query          An associative array of WP_Meta_Query arguments.
 	 *                                                See WP_Meta_Query::__construct for accepted values.
-	 *     @type string          $capability          An array or a comma-separated list of capability names that users must match
+	 *     @type string|string[] $capability          An array or a comma-separated list of capability names that users must match
 	 *                                                to be included in results. Note that this is an inclusive list: users
 	 *                                                must match *each* capability.
 	 *                                                Does NOT work for capabilities not in the database or filtered via {@see 'map_meta_cap'}.