Mention removal of SYSTEM_CONFIG table

Change-Id: Ia6c79d81f5682637006fdb2c635ba20ebf81b8c7
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index 01638df..1e54a94 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -150,6 +150,11 @@
 element and extensibility, compared to Pegdown speed that was, in general, less than
 ideal and for pathological input either hangs or practically hangs during parsing.
 
+### SYSTEM_CONFIG table is removed
+
+This table was used to retrieve the `site_path` directory in unattended setup
+mode. As a replacement, system property `gerrit.site_path` should be used.
+
 ## New Features
 
 ### REST API
@@ -361,4 +366,4 @@
 
 * Add API and REST endpoints to get/set default edit preferences in [`Server`](https://gerrit.googlesource.com/gerrit/+/stable-2.16/java/com/google/gerrit/extensions/api/config/Server.java).
 
-* Allow to filter list by project state in [`Projects`](https://gerrit.googlesource.com/gerrit/+/stable-2.16/java/com/google/gerrit/extensions/api/projects/Projects.java).
\ No newline at end of file
+* Allow to filter list by project state in [`Projects`](https://gerrit.googlesource.com/gerrit/+/stable-2.16/java/com/google/gerrit/extensions/api/projects/Projects.java).