Fix crash on startup if auto mark-as-read is disabled.
Fix crash on startup if auto mark-as-read is disabled.

CCBUG: 116514

svn path=/trunk/KDE/kdepim/knode/; revision=491989

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