libwebsockets

ws-over-h2: wrong sid on rst_stream

rst_stream is almost always called from the h2 parser... in the case
a ws-over-h2 is closing though, it can't reference the h2n parser sid
context to get the sid to send... it's unrelated at that time.

https://bugzilla.mozilla.org/show_bug.cgi?id=1590299
https://github.com/warmcat/libwebsockets/issues/1752