docs(changelog) added missing entries for 2.4.0 release (Kong#7033)

Author: locao

CHANGELOG.md

@@ -99,6 +99,8 @@ repository will allow you to do both easily.
   [#6958](https://github.com/Kong/kong/pull/6958)
 - Bump lua-cassandra from 1.5.0 to 1.5.1
   [#6857](https://github.com/Kong/kong/pull/6857)
+- Bump luasyslog from 1.0.0 to 2.0.1
+  [#6957](https://github.com/Kong/kong/pull/6957)
 
 ### Additions
 
@@ -192,6 +194,8 @@ repository will allow you to do both easily.
   [7002](https://github.com/Kong/kong/pull/7002)
 - Do not assume upstreams do not exist after init phase.
   [7010](https://github.com/Kong/kong/pull/7010)
+- Do not overwrite configuration files when running migrations.
+  [7017](https://github.com/Kong/kong/pull/7017)
 
 ##### PDK