Fallback to LevelRaw if Level is not in the RenderingInfo of the XML …

…event (elastic#4257)

If the Level is not in the RenderingInfo section of the event, fallback on the raw level. Applies to Windows Vista and above only.

https://discuss.elastic.co/t/event-fields-missing-if-renderinginfo-is-empty/84709

(cherry picked from commit c18adce)

CHANGELOG.asciidoc

@@ -81,6 +81,7 @@ https://github.com/elastic/beats/compare/v5.4.1...master[Check the HEAD diff]
 *Packetbeat*
 
 *Winlogbeat*
+- Add the ability to use LevelRaw if Level isn't populated in the event XML. {pull}4257[4257]
 
 ==== Deprecated