docs: Remove outdated warning for plugins.security.nodes_dn (#156)

Author: siegfriedweber

docs/modules/opensearch/pages/usage-guide/security.adoc

@@ -182,13 +182,6 @@ Defaults to the `tls` SecretClass and can't be disabled.
 <3> The lifetime for autoTls certificates generated by the secret operator.
 Only a lifetime up to the `maxCertificateLifetime` setting in the SecretClass is applied.
 
-[IMPORTANT]
-====
-The operator sets the configuration `plugins.security.nodes_dn` to `["CN=generated certificate for pod"]`, which provides weak authentication between nodes.
-For enhanced security, use certificates that uniquely identify the OpenSearch nodes.
-In this case, you must also adapt the `plugins.security.nodes_dn` setting via configOverrides.
-====
-
 == Disabling security
 
 The OpenSearch security plugin can be disabled as follows: