Tweak KCM

Summary: Tweaking the text a little leads to a window size that doesn't cut off the refresh button when no device is selected.

Test Plan:
Before:

After:

Reviewers: KDE Connect, albertvaka

Reviewed By: KDE Connect, albertvaka

Subscribers: KDE Connect

Tags: KDE Connect

Differential Revision: https://phabricator.kde.org/D10287