Fix XML namespace parsing issues.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12922 e27351fd-9f3e-4f54-a53b-843176b1656c
Another XML fix.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12923 e27351fd-9f3e-4f54-a53b-843176b1656c