add a changelog note about the prior Makefile update

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52ee21eef7c6295f0a2e3964b9bb4b4f9ccc0cbf..66b533320618f511dc9ba221362afa33bd76e484 100644 (file)
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - the packaging work flow on CentOS 7 now selects the Python 3 bindings, instead
   of Python 2 bindings
 - remove Python 2 bindings #1992
+- improved thread-safety in Graphviz bindings Makefile
 
 ### Fixed