fix case-miss when prep_and_validate_update is called on doc with attachment stubs
fix case-miss when prep_and_validate_update is called on doc with attachment stubs


git-svn-id: cddd53339f8fd45d5e26e8b408ccee250f6290a7@754578 13f79535-47bb-0310-9956-ffa450edef68

benoitc/couchdb-old,benoitc/couchdb-old,benoitc/couchdb-old,benoitc/couchdb-old,benoitc/couchdb-old