important bugfix: Avoid CRASH if users adds a new folder after (s)he has clicked on the top level folder list entry.  (background: if top level entry is active the member mFolder is zero, so asking mFolder->needsRepainting() results in a crash)
important bugfix: Avoid CRASH if users adds a new folder after (s)he has clicked on the top level folder list entry.  (background: if top level entry is active the member mFolder is zero, so asking mFolder->needsRepainting() results in a crash)

svn path=/trunk/kdenetwork/kmail/; revision=160305

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