class PPDContext actually looks harmless but it has an out-of-line
destructor so the plugin can't see that it's harmless, so use
default destructor instead.

Change-Id: I921a4cdaeb5c8fe286615162b9e9c2a8db47b300
Reviewed-on: https://gerrit.libreoffice.org/42633Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>