Fixes #7028 PHP Notice: Undefined property: stdClass::$table_name whe…

…n enable database options on apache server (#7031)

inc/Engine/Admin/Database/OptimizationProcess.php

@@ -124,7 +124,7 @@ protected function task( $item ) {
 				}
 				break;
 			case 'database_optimize_tables':
-				$query = $wpdb->get_results( "SELECT table_name, data_free FROM information_schema.tables WHERE table_schema = '" . DB_NAME . "' and Engine <> 'InnoDB' and data_free > 0" );
+				$query = $wpdb->get_results( "SELECT table_name AS table_name, data_free AS data_free FROM information_schema.tables WHERE table_schema = '" . DB_NAME . "' and Engine <> 'InnoDB' and data_free > 0" );
 				if ( $query ) {
 					$number = 0;
 					foreach ( $query as $table ) {