Only resize data structures used for threading if threading is turned on at all for this folder.
Only resize data structures used for threading if threading is turned on
at all for this folder.

svn path=/trunk/kdepim/; revision=261396

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