Fix GeoIP stats API response (#2818)

Author: pquentin

output/openapi/elasticsearch-openapi.json

@@ -29,9 +29,11 @@ export class GeoIpDownloadStatistics {
   /** Total milliseconds spent downloading databases. */
   total_download_time: DurationValue<UnitMillis>
   /** Current number of databases available for use. */
-  database_count: integer
+  databases_count: integer
   /** Total number of database updates skipped. */
   skipped_updates: integer
+  /** Total number of databases not updated after 30 days */
+  expired_databases: integer
 }
 
 /** Downloaded databases for the node. The field key is the node ID. */