update CHANGELOG.next.asciidoc

CHANGELOG.next.asciidoc

@@ -258,7 +258,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 ==== Added
 
 *Affecting all Beats*
-
+- FileBeat IIS module will not parse and extra IP address in the end of each log line, which is usually used with the X-Forwarded-For header {pull}19142[192142]
 - Add document_id setting to decode_json_fields processor. {pull}15859[15859]
 - Include network information by default on add_host_metadata and add_observer_metadata. {issue}15347[15347] {pull}16077[16077]
 - Add `aws_ec2` provider for autodiscover. {issue}12518[12518] {pull}14823[14823]