matroskamux: Do caps renegotiation when it only adds fields
Matroskamux can accept caps renegotiation if the new caps is a superset of the old one, meaning upstream added new info to the caps.
Same logic as a5f22f03 in qtmux.
Matroskamux can accept caps renegotiation if the new caps is a superset of the old one, meaning upstream added new info to the caps.
Same logic as a5f22f03 in qtmux.