Docs: Add a missing summary and @since version to the DocBlock for wp_xmlrpc_server::serve_request().

Introduced in [11789].

See #32246.


git-svn-id: https://develop.svn.wordpress.org/trunk@35956 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-xmlrpc-server.php

@@ -188,6 +188,9 @@ class wp_xmlrpc_server extends IXR_Server {
 	}
 
 	/**
+	 * Serves the XML-RPC request.
+	 *
+	 * @since 2.9.0
 	 * @access public
 	 */
 	public function serve_request() {