An error on mqtt add-on with nginx

Installation Home Assistant OS
1

Hi all,
I’m trying to configure MQTT Server & Web client add-on.
this is my conf

ssl: false
certfile: /ssl/sk2mc.duckdns.org.crt
keyfile: /ssl/sk2mc.duckdns.org.key
broker: true
allow_anonymous: true
mqttusers:
  - username: mosquitto
    password: XXXXXXXXXXXXXXXXXX
    readonly: false
    topics:
      - '#'

the add-on starts an infinite list of this kind of error
[23:02:05] INFO: Starting NGINX for the MQTT client…
nginx: [emerg] invalid port in “:” of the “listen” directive in /etc/nginx/servers/ingress.conf:2

How could I fix it?