Update 2.15.10 release notes

Change-Id: I464b6019a5ad98d2a2fa5bdf0f10706e728583fa
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index 2ac4d2d..5936028 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -405,6 +405,9 @@
 
 * Add support for Elasticsearch 6.6.
 
+* [Issue 10428](https://bugs.chromium.org/p/gerrit/issues/detail?id=10428):
+Fix binding of AuditListeners for plugin tests.
+
 * PolyGerrit fixes
 
   * Add warning that Javascript is required to use PolyGerrit.