D23339: Fix memory leak in ConfigView and Dialog

[Daniel Vrátil]

dvratil added reviewers: Plasma, Frameworks.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D23339

To: dvratil, #plasma, #frameworks
Cc: kde-frameworks-devel, LeGast00n, cblack, GB_2, michaelh, ngraham, bruns