Fix an unread messages of by one problem for newly created folder and for imap folders.
Fix an unread messages of by one problem for newly created folder and for imap
folders.

svn path=/trunk/kdenetwork/kmail/; revision=84785

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