in createDavItem(), if the DavProtocolAttribute is 0, then we can't

get the mimetype for vcards from the DavProtocol.  In this case,
assume the mimetype is the KABC::Addressee:mimeType().

BUG: 292647
MERGE: 4.8
FIXED-IN: 4.8.1
(cherry picked from commit 7820402d)