Fix issue seen when migrating a user with a shared calendar and a shadowed timezone property.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@11972 e27351fd-9f3e-4f54-a53b-843176b1656c
Fix issue seen when migrating a user with a shared calendar and a shadowed timezone property.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@11973 e27351fd-9f3e-4f54-a53b-843176b1656c