1) preview filter needs libdv, so add %%WITH_LIBDV%%
2) remove %%WITH_OGG%% for the ogg import/export filters since
transcode builds the modules anyway. `strings export_ogg` reveals
that ogg shell tools are used but their existance is not tested.
PR: 51917
Submitted by: Hendrik Scholz <hendrik@scholz.net>
991ad65800