Merge branch 'branch-0.5.0' into 'branch-0.5.0'

update changelog

See merge request megasearch/milvus!569

Former-commit-id: 4f355bdca1f4f9331b05b567171ac081f1d00323

cpp/CHANGELOG.md

@@ -8,6 +8,7 @@ Please mark all change in change log and use the ticket from JIRA.
 
 ## Improvement
 - MS-552 - Add and change the easylogging library
+- MS-553 - Refine cache code
 
 ## New Feature