use of undefined constant ZBX_FLAG_DISCOVERY_CHILD when importing a host

Try to import attached XML into Zabbix 2.2. Import succeeds, but also prints the following in red color:

Use of undefined constant ZBX_FLAG_DISCOVERY_CHILD - assumed 'ZBX_FLAG_DISCOVERY_CHILD' [conf.import.php:130 ? CConfigurationImport->import() ? CConfigurationImport->processTriggers() ? CImportReferencer->resolveTrigger() ? CImportReferencer->selectTriggers() in frontends/php/include/classes/import/CImportReferencer.php:753]