Remove the misleading comment (#26838)

* Remove the misleading comment

Signed-off-by: tyxia <tyxia@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 7e4dbfbeb93776a6a4830a2b5b6f067cff6029da

envoy/extensions/filters/http/gcp_authn/v3/gcp_authn.proto

@@ -26,8 +26,7 @@ message GcpAuthnFilterConfig {
   // The URL format is "http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/identity?audience=[AUDIENCE]"
   config.core.v3.HttpUri http_uri = 1 [(validate.rules).message = {required: true}];
 
-  // Retry policy for fetching tokens.
-  // This field is optional. If it is not configured, the filter will be fail-closed (i.e., reject the requests).
+  // Retry policy for fetching tokens. This field is optional.
   config.core.v3.RetryPolicy retry_policy = 2;
 
   // Token cache configuration. This field is optional.