add docs for iml backup server check

docs/20_Checks/_index.md

@@ -8,7 +8,6 @@ There is one include script used by all checks:
 ## Check scripts
 
 * [check_apache_requests](check_apache_requests.md)
-* check_backup_one
 * [check_ceph_diskfree](check_ceph_diskfree.md)
 * [check_ceph_io](check_ceph_io.md)
 * [check_ceph_osd](check_ceph_osd.md)
@@ -26,6 +25,7 @@ There is one include script used by all checks:
 * [check_haproxy_health](check_haproxy_health.md)
 * [check_haproxy_status](check_haproxy_status.md)
 * [check_http](check_http.md)
+* [check_iml_backup_server](check_iml_backup_server.md)
 * [check_journallog](check_journallog.md)
 * [check_memory](check_memory.md)
 * [check_mysqlserver](check_mysqlserver.md)