Don't duplicate categories, when changing filters.
Don't duplicate categories, when changing filters.

svn path=/trunk/kdepim/; revision=142827

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