PRIORITY frames from server should be Connection Error

[martinduke]

the very end of Section 4.2.3 of quic-http says:

PRIORITY frames received by a client MUST be treated as a stream
error of type HTTP_UNEXPECTED_FRAME.

Elsewhere, this kind of thing is a connection error. Making this a stream error seems problematic; if otherwise valid, if this goes out on the control stream a stream error may bring everything down anyway?

Here is the mailing list thread:
https://mailarchive.ietf.org/arch/msg/quic/ODlqMOxUP9W5RcZ5UIjTp2lKh4U

I believe the consensus is to make it a conn error; PR to follow.