Drop unused KF5DocTools, add missing KF5Completion

Authored by asturmlechner on Jun 20 2019, 10:11 AM.

Description

Drop unused KF5DocTools, add missing KF5Completion

Test Plan: Builds fine after change.

Reviewers: ngraham, cfeck

Reviewed By: ngraham

Differential Revision: https://phabricator.kde.org/D21921