Text flicker fix

Reverts NeArnold's change to TaskListDlg.h.SetList()

NeArnold's change causes any text in the Task list panel in Npp to flicker on redraw as the user types in the document AND I cannot recreate the issue he was trying to solve in the first place.

Temporary fix (until I can get around to doing a PR): in %ProgramFiles%\Notepad++\plugins\NppTaskList (also accessible via Plugins>Open plugins folder in Npp), replace NppTaskList.dll (this may be an administrator action) with the file attached to this release.