Merge pull request #3228 from ewolinetz/update_secure_forward_docs

Clarifying current limitation with forwarding to Logstash

Author: ahardin-rh

install_config/aggregate_logging.adoc

@@ -918,12 +918,6 @@ plug-in it provides:
 </source>
 ----
 
-If the external aggregator is Logstash, with Logstash 2.4 it can be configured to
-interpret messages from
-link:https://www.elastic.co/guide/en/logstash/current/plugins-codecs-fluent.html[Fluentd]
-and can be configured to use
-link:https://www.elastic.co/guide/en/logstash/current/plugins-inputs-tcp.html#ssl_enable[SSL].
-
 Further explanation of how to set up the `fluent-plugin-secure-forward` plug-in
 can be link:https://github.com/tagomoris/fluent-plugin-secure-forward[found
 here].