Change position of label in SaveOptions.ui

Summary:
Changed position of message to change image quality.
I think the label is better read before the compression quality bar.
I used Qt Designer for this.

Before:

After:

Reviewers: Spectacle, VDG, ngraham, davidre

Reviewed By: Spectacle, VDG, ngraham, davidre

Subscribers: davidre, ngraham

Tags: Spectacle

Differential Revision: https://phabricator.kde.org/D29113