Use get_by_id instead for picking up clients, in order to have same draft mode behavior

Author: almirbi

inc/types/class-base.php

@@ -39,7 +39,7 @@ public function handle_authorisation() {
 		$scope        = isset( $_GET['scope'] ) ? wp_unslash( $_GET['scope'] ) : null;
 		$state        = isset( $_GET['state'] ) ? wp_unslash( $_GET['state'] ) : null;
 
-		$client = Client::get_by_client_id( $client_id );
+		$client = Client::get_by_id( $client_id );
 		if ( empty( $client ) ) {
 			return new WP_Error(
 				'oauth2.types.authorization_code.handle_authorisation.invalid_client_id',