Fix types

Author: chrisronline

x-pack/plugins/monitoring/server/lib/alerts/fetch_legacy_alerts.ts

@@ -86,6 +86,7 @@ export async function fetchLegacyAlerts(
       message: get(hit, '_source.message'),
       resolved_timestamp: get(hit, '_source.resolved_timestamp'),
       nodes: get(hit, '_source.nodes'),
+      nodeName: '', // This is set by BaseAlert
       metadata: get(hit, '_source.metadata') as LegacyAlertMetadata,
     };
     return legacyAlert;