Improve warning message.
Improve warning message.

svn path=/trunk/KDE/kdepim/kleopatra/; revision=802114

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