Add changelog entry

Author: robertbrignull

extensions/ql-vscode/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [UNRELEASED]
 
+- Fix bug where the "CodeQL: Set Current Database" command didn't always select the database. [#2384](https://github.com/github/vscode-codeql/pull/2384)
+
 ## 1.8.3 - 26 April 2023
 
 - Added ability to filter repositories for a variant analysis to only those that have results [#2343](https://github.com/github/vscode-codeql/pull/2343)