Update Changelog: Cloud/User: Renamed User.GetSelf to User.GetCurrentUser

Author: andygrunwald

CHANGELOG.md

@@ -397,6 +397,7 @@ client, err := jira.NewClient("https://...", tp.Client())
 * Cloud/Authentication: `BasicAuthTransport.Password` was renamed to `BasicAuthTransport.APIToken`
 * Cloud/Authentication: Removes `CookieAuthTransport` and `AuthenticationService`, because this type of auth is not supported by the Jira cloud offering
 * Cloud/Component: The type `CreateComponentOptions` was renamed to `ComponentCreateOptions`
+* Cloud/User: Renamed `User.GetSelf` to `User.GetCurrentUser`
 
 ### Features