Update plasma5-workspace to version 5.21.1 / rev 159 via SR 875514
    
    https://build.opensuse.org/request/show/875514
    by user Vogtinator + RBrownSUSE
    - Add back patch for fix which didn't make it into 5.21.1:
      * 0001-locations-runner-Fix-empty-list-on-invalid-shell-quo.patch
    
    - Update to 5.21.1
      * New bugfix release
      * For more details please see:
      * https://kde.org/announcements/plasma/5/5.21.1
    - Changes since 5.21.0:
      * Fix case in logout applet config key (kde#433320)
      * calculatorrunner: Fix mixed hex+decimal calculations (kde#431362)
      * Fix font installation
      * locations runner: Fix absolute filepath + arguments (kde#433053)
      * Enforce SESSION_MANAGER is exported before plasmashell is started
      * libtaskmanager: Allow to launch executables (kde#433148)
      * Move ksmserver's ksplash notifying to ksmserver (kde#432364)
      * Handle closeSession being called concurrently
      * [libkworkspace] Interim fix for the logout issue (kde#4