[Dev] Heads-up: remove '.schema' from certificate parcel refs

[Phillip J. Eby]

Earlier today I flattened the certstore.schema parcel out of existence, but 
forgot to post a warning; you need to change any references to 
'osaf.framework.certstore.schema' to refer to 'osaf.framework.certstore' 
instead.  If you get a ParcelException referencing certstore, this is 
probably the problem.

Sorry about the late notice; I had changed my own certificate example 
parcel a week or so ago, and since it's not in subversion I missed it in 
the diffs I checked in today.