2.16: Mention JGit upgrade

Change-Id: I6550ef0c0cfea48e6b0246cbffcadbf1913c31a6
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index db0b1fc..9598390 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -171,6 +171,8 @@
 
 * Update guice-* to 4.2.1
 
+* Update JGit to 5.1.3.201810200350-r
+
 * Update Lucene to 6.6.5
 
 * Update mime4j to 0.8.1