KDE Plasma Desktop: update to 5.17.5

Tuesday, 7 January 2020. Today KDE releases a bugfix update to KDE Plasma 5,
versioned 5.17.5. Plasma 5.17 was released in October 2019 with many feature
refinements and new modules to complete the desktop experience.

This release adds a month's worth of new translations and fixes from KDE's
contributors. The bugfixes are typically small but important and include:

• Fix for KDecoration crash in systemsettings. Commit. Fixes bug #411166.
• Fix regression in "Port the pager applet away from QtWidgets".
• Revert "[sddm-theme] Fix initial focus after SDDM QQC2 Port".

Full Plasma 5.17.5 changelog:

https://kde.org/announcements/plasma-5.17.4-5.17.5-changelog.php