Saving after reordering jobs enabled

Summary: When pressing the "move up" or "move down" buttons in the scheduler, the scheduler job is not marked to be changed. Hence, pressing the save button has no effect. This patch corrects this.

Test Plan: Create a schedule with at least two jobs in the table. Check, whether changing the sequence order enables saving the scheduler job.

Reviewers: mutlaqja, TallFurryMan

Reviewed By: mutlaqja

Subscribers: kde-edu

Tags: KDE Edu

Differential Revision: https://phabricator.kde.org/D20716