Update 2.15.13 release notes

Change-Id: I2b5dd13caed148d5e5416c5a589f7df419aa7486
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index 13b81ac..551049f 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -420,6 +420,13 @@
 
 ### 2.15.13
 
+* [Issue 10695](https://bugs.chromium.org/p/gerrit/issues/detail?id=10695):
+Upgrade JGit to 4.9.10.201904181027-r to fix regression in packfile list
+handling.
+
+  If `core.trustfolderstat` was set to `false`, an infinite loop could occur
+  when an object was not found in the packfile.
+
 * Add support for Elasticsearch 6.7.x and 7.0.x.
 
   The elasticsearch-rest-client is upgraded to 7.0.0.