Fix changelog & forward-port entry for 0.12.4

Signed-off-by: Matthias Rampke <[email protected]>

Author: matthiasr

CHANGELOG.md

@@ -1,6 +1,10 @@
 ## 0.13.1 / 2022-12-05
 
-* Fix authentication bypass [GHSA-7rg2-cxvp-9p7p](https://github.com/advisories/GHSA-7rg2-cxvp-9p7p) ([#209](https://github.com/prometheus/graphite_exporter/pull/209))
+* [SECURITY] Fix authentication bypass [GHSA-7rg2-cxvp-9p7p](https://github.com/advisories/GHSA-7rg2-cxvp-9p7p) ([#209](https://github.com/prometheus/graphite_exporter/pull/209))
+
+## 0.12.4 / 2022-12-05
+
+* [SECURITY] Fix [GHSA-7rg2-cxvp-9p7p](https://github.com/advisories/GHSA-7rg2-cxvp-9p7p) (manual backport of [#209](https://github.com/prometheus/graphite_exporter/pull/209))
 
 ## 0.13.0 / 2022-10-25