remove duplicate include kvbox.h
remove duplicate include kvbox.h

svn path=/trunk/KDE/kdepim/; revision=771053

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