D7967: KComboBox: Return early when setting editable to previous value

[Aleix Pol Gonzalez]

apol accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R284 KCompletion

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D7967

To: mwolff, apol
Cc: #frameworks