Mention BC update in 2.15.7

Change-Id: I5c8f4bf092918b68dbbf5785798cd2986f115d2a
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index b318eee..dfafda8 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -373,7 +373,7 @@
 
 * Update Blame Cache to 0.2-5
 
-* Update Bouncy Castle to 1.57
+* Update Bouncy Castle to 1.57 (updated to 1.60 in 2.15.7)
 
 * Update Dropwizard to 3.2.4