MINOR: mux-h1: Disable reads if an error was reported on the H1 stream

MINOR: mux-h1: Disable reads if an error was reported on the H1 stream

Don't try to read more data if a parsing or a formatting error was reported
on the H1 stream. There is no reason to continue to process the messages for
the current connection in this case. If a parsing error occurs, it means the
input is invalid. If a formatting error occurs, it is an internal error and
it is probably safer to give up.