data & debian: Replace QtMir's X11 logo with Suru-themed one

Source: https://github.com/gusbemacbe/suru-plus/blob/9bd895f324051ed9ba26e5981dd995376e5e572a/Suru%2B%2B/apps/scalable/xfig.svg

Licenses:

• CC BY-SA/GPL3 © 2018-2019 Suru Icons by Sam Hewitt.
• GPL3 © 2018-2019 Suru++ Ubuntu by Andrea Bonanni and Gustavo Costa.
• GPL3 © 2018-2019 Suru++ 25 by Gustavo Costa.
• GPL3 © Papirus by Alexey Varfolomeev.
• GPL3 © Numix by Numix Team.
• GPL3/MIT © 2015-2019 La Capitaine by Keefer Rourke.
• MIT © Icons 8 by Gravit Designer¹
• MIT © Twemoji by Twitter Team.