Docs: Remove an empty line between @param and @return tags, per the documentation standards.

See #49572.

git-svn-id: https://develop.svn.wordpress.org/trunk@48102 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -509,7 +509,6 @@ class WP_Network_Query {
 	 *
 	 * @param string   $string  Search string.
 	 * @param string[] $columns Array of columns to search.
-	 *
 	 * @return string Search SQL.
 	 */
 	protected function get_search_sql( $string, $columns ) {