Troubleshooting monitoring in Logstash

When upgrading from older versions, the built-in logstash_system user is disabled for security reasons. To resume monitoring:

1. Change the logstash_system password:

   				PUT _security/user/logstash_system/_password
   					{
     "password": "newpassword"
   }
   		

2. Re-enable the logstash_system user:

   				PUT _security/user/logstash_system/_enable