trace-events: Drop orphaned monitor trace event Event monitor_protocol_event is unused since commit 7517517. Drop it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-id: 1411476811-24251-4-git-send-email-armbru@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>