BUG/MINOR: mux-h2: Obey dontlognull option during the preface

If a connection is closed during the preface while no data are received, if
the dontlognull option is set, no log message must be emitted. However, this
will still be handled as a protocol error. Only the log is omitted.

This patch should fix the issue #1336 for H2 sessions. It must be backported
to 2.4 and 2.3 at least, and probably as far as 2.0.
1 file changed