add telegraf user-agent for http_response plugin

roles/probe/templates/telegraf/probe.conf.j2

@@ -25,6 +25,9 @@
   [inputs.http_response.tags]
     name = {{ http_url.name | default(http_url.url) | to_json }}
 
+  [inputs.http_response.headers]
+    User-Agent = "telegraf/{{ ansible_fqdn }}"
+
 {% endfor %}
 
 [[inputs.ping]]

roles/telegraf/templates/telegraf/global.conf.j2

@@ -6,7 +6,6 @@
 [agent]
   ## Override default hostname, if empty use os.Hostname()
   hostname = "{{ ansible_fqdn }}"
-  user_agent = "telegraf/{{ ansible_fqdn }}"
 
 
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