Fix creating items with a single external payload.
Review Request #111819 - Created July 31, 2013 and submitted
Fix creating items with a single external payload. This was removing the just inserted part from the db again, but keeping the external payload file around. This cannot possibly have ever worked... We probably didn't notice this so far since emails are multi-part and don't hit this path at all, and everything else is usually too small for the external storage threshold. This was found by the unit tests for ItemCreateJob in kdepimlibs.