doc/manage_agents.txt: minor update

Author: icy

doc/manage_agents.txt

@@ -23,10 +23,9 @@ case, you should ensure that you new agent has an unique name/id. You can
 simply know that by using `manage_agents -l` to list all known agents.
 
 For more details, please refer to OSSEC document
-    http://www.ossec.net/doc/manual/agent/agent-management.html
+    https://www.ossec.net/docs/manual/agent/agent-management.html
 
-PS: you may use some tools (`expect`) to send strings to `manage_agents`,
-instead of using the above environment variables. It's your choice.
+== Notes ==
 
---
-Anh K. Huynh <[email protected]>
+You can also use some tools (`expect`) to send strings to `manage_agents`,
+instead of using the above environment variables.