Fix crash in korganizer's purge completed todo.
Fix crash in korganizer's purge completed todo.

svn path=/branches/KDE_3_3_BRANCH/kdepim/; revision=337888

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi