Update Wazuh Agent registration task with new "agent_name" var

roles/wazuh/ansible-wazuh-agent/tasks/Linux.yml

@@ -51,7 +51,7 @@
     - name: Linux | Register agent (via authd)
       shell: >
         /var/ossec/bin/agent-auth
-        -A {{ agent_name }}
+        {% if wazuh_agent_authd.agent_name is not none %}-A {{ agent_name }} {% endif %}
         -m {{ wazuh_managers.0.address }}
         -p {{ wazuh_agent_authd.port }}
         {% if wazuh_agent_nat %}-I "any" {% endif %}