scaling lists not functional with 4:4:4

[Steve Borho]

If scaling lists are enabled with 4 :4 :4 encodes, we see hash errors in the HM Rext decoder.

4 :2 :0 and 4 :2 :2 seem to be ok. For the 1.3 release, we will disable scaling lists for 4 :4 :4. This needs a proper long-term fix

[Steve Borho]

encoder: do not allow scaling lists to be used with 4:4:4 color space (refs #72)

It causes hash mistakes

→ <<cset 3badda1ceda6>>

[Pradeep Ramachandran]

Changeset 2b01f8c4138a fixes the issue