LogStash Grok - Match Nginx error - With multiline errors

logstash-nginx-error.conf

input {
    stdin {
    }
}

filter {
    mutate {
        replace => {
            "type" => "nginx-error"
        }
    }
    multiline {
        negate => 'true'
        pattern => "^%{YEAR}/%{MONTHNUM}/%{MONTHDAY}"
        what => 'previous'
    }
    mutate {
        gsub => [ "message", "\r", "" ]
    }
    grok {
        match => [
            "message", "(?<timestamp>\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2}) \[%{DATA:nginx_severity}\] %{NOTSPACE} %{NOTSPACE} (?<nginx_message>(.|\r|\n)*)(?:, client: (?<nginx_client_ip>%{IP}|%{HOSTNAME}))(?:, server: %{IPORHOST:nginx_server})(?:, request: %{QS:nginx_request})?(?:, host: %{QS:nginx_host})?(?:, referrer: \"%{URI:nginx_referrer})?"
        ]
    }
    mutate {
        remove_tag => [ "multiline" ]
    }
    date {
        match => [ "timestamp" , "yyyy/MM/dd HH:mm:ss" ]
        timezone => 'UTC'
    }
}

output {
    stdout { codec => rubydebug }
}