update the changelog.md

Author: lijinpei2008

src/Monitor/Monitor/ChangeLog.md

@@ -19,6 +19,7 @@
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 ## Upcoming Release
+* Fixed an issue where users could not correctly ignore warning messages after setting environment variables [#17013]
 
 ## Version 3.0.0
 * Added new properties EventName, Category, ResourceProviderName, OperationName, Status, SubStatus with type string as output for command Get-AzLog [#15833]