Deoldify Vapoursynth filter

[Selur]

Updated the download to make sure ScFrameDir/sc_framedir is only set when set by the user, otherwise it stays at None.
This causes:

clip = HAVC_main(clip=clip, EnableDeepEx=True, DeepExMethod=1, DeepExRefMerge=0, DeepExModel=1)

to fail with:

HAVC_deepex: method != 0 but sc_framedir is unset

=> I'll adjust Hybrid to set ScFrameDir if it's empty.
=> Updated the download
Cu Selur