The kde4 VCL Plugin was removed with
6ca3b364, so drop some
now superfluous leftovers.

Change-Id: I92887b679462a6ac22c3668a24ec6a9fdee8fac1
Reviewed-on: https://gerrit.libreoffice.org/67047
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>