update changelog.md

remove the SRP SDK upgrade information

Author: blueww

src/ResourceManager/Storage/ChangeLog.md

@@ -18,8 +18,7 @@
         - Additional information about change #1
 -->
 ## Current Release
-* Upgrade SRP SDK to 6.3.1
-* Add IdentityType setting support to resource mode storage account cmdlets
+* Add AssignIdentity setting support to resource mode storage account cmdlets
     - New-AzureRmStorageAccount
     - Set-AzureRmStorageAccount
 * Add Customer Key Support to resource mode storage account cmdlets
@@ -46,4 +45,4 @@
 
 ## Version 2.4.0
 
-## Version 2.3.0
+## Version 2.3.0