Update changelog for 1.15.1, 2nd time. (#10726)

Author: sean-mcmanus

Extension/CHANGELOG.md

@@ -1,8 +1,9 @@
 # C/C++ for Visual Studio Code Changelog
 
-## Version 1.15.1: March 21, 2023
+## Version 1.15.1: March 22, 2023
 ### Bug Fixes
 * Fix crashes with a multiroot workspace. [#10636](https://github.com/microsoft/vscode-cpptools/issues/10636)
+* Fix a deadlock with a multiroot workspace. [#10719](https://github.com/microsoft/vscode-cpptools/issues/10719)
 
 ## Version 1.15.0: March 15, 2023
 ### Enhancements