fix: update changelog

Author: jcnelson

CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to the versioning scheme outlined in the [README.md](RE
 ### Fixed
 
 - Handle the case where a bitcoin node returns zero headers (#3588)
+- The default value for `always_use_affirmation_maps` is now set to `false`,
+  instead of `true`.  This was preventing testnet nodes from reaching the chain
+tip with the default configuration.
 
 ## [2.1]