do not crash if the signature has no fingerprint
do not crash if the signature has no fingerprint

svn path=/branches/kdepim/enterprise4/kdepim/; revision=822161

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