Fix/mongodb auth conf

[AlvaroVega]

#1736

• Checked

This is really a small improvement, mongoose does not need options.auth, just auth in in url, so this PR removes it for mongoose

[AlvaroVega]

Tested with:

iot-mongo2:
  container_name: iot-mongo2
  hostname: iot-mongo2
  restart: "unless-stopped"
  image: mongo:8.0.5   
  ports:
    - "27018:27017"
  command: ["mongod", "--auth"]
  environment:
    MONGO_VERSION: 8.0.5
    MONGO_INITDB_ROOT_USERNAME: root
    MONGO_INITDB_ROOT_PASSWORD: example123
    MONGO_INITDB_DATABASE: admin  
  log_driver: json-file
  log_opt:
    max-size: "250m"

  environment:
    - IOTA_MONGO_HOST=iot-mongo2
    - IOTA_MONGO_PORT=27017
    - IOTA_MONGO_DB=iotajson
    - IOTA_MONGO_USER=pepe
    - IOTA_MONGO_PASSWORD=pepepasswd

$ docker exec -it iot-mongo2 mongosh -u root -p example123 --authenticationDatabase admin

use iotajson

db.createUser({
  user: "pepe",
  pwd: "pepepasswd",
  roles: [
    { role: "readWrite", db: "iotajson" }
})

[AlvaroVega]

also tested with:

- IOTA_MONGO_AUTH_SOURCE=admin

and

$ docker exec -it iot-mongo2 mongosh -u root -p example123 --authenticationDatabase admin

use iotajson

db.createUser({
  user: "pepe",
  pwd: "pepepasswd",
  roles: [
    { role: "readWrite", db: "iotajson" }
})

[AlvaroVega]

@FukayaTakashi what do you think ?

[fgalan]

LGTM

Waiting to @FukayaTakashi feedback before merging