D12095: convert setDirLister to the new connect syntax

[Aleix Pol Gonzalez]

apol accepted this revision.

REPOSITORY
  R241 KIO

REVISION DETAIL
  https://phabricator.kde.org/D12095

To: jtamate, dfaure, #frameworks, apol
Cc: apol, michaelh, ngraham, bruns