Simplify testing with TLS (#4095)

plugins/inputs/nginx/README.md

@@ -8,11 +8,11 @@
   ## An array of Nginx stub_status URI to gather stats.
   urls = ["http://localhost/server_status"]
 
-  ## Optional SSL Config
-  # ssl_ca = "/etc/telegraf/ca.pem"
-  # ssl_cert = "/etc/telegraf/cert.pem"
-  # ssl_key = "/etc/telegraf/key.pem"
-  ## Use SSL but skip chain & host verification
+  ## Optional TLS Config
+  # tls_ca = "/etc/telegraf/ca.pem"
+  # tls_cert = "/etc/telegraf/cert.pem"
+  # tls_key = "/etc/telegraf/key.pem"
+  ## Use TLS but skip chain & host verification
   # insecure_skip_verify = false
 
   ## HTTP response timeout (default: 5s)