Fix Elasticsearch version in 2.16 release notes

Change-Id: Ib6858e4c3fdb75c694af4ac8bbac2d7efa52c1d3
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index fc787f1..f4bfbf8 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -352,7 +352,7 @@
 
 * Update Dropwizard metrics-core to 3.2.5
 
-* Update elasticsearch to 2.4.6
+* Update Elasticsearch to 6.4.3
 
 * Add dependency to flexmark-java 0.34.18