Update alert using 'fields' is not working

[mgabriel-silva]

Request Type

Bug

Work Environment

Question	Answer
TheHive4py version / git hash	1.5.1

Problem Description

When using 'fields' to update only 'customFields', it's updating other fields as well.

Steps to Reproduce

1. Create an Alert with no artifacts based on an existing alert (I'm using object from thehivehooks)

alert = Alert(
        title = event['object'].get('title', ''),
        type = event['object'].get('type', ''),
        source = event['object'].get('source', ''),
        sourceRef = event['object'].get('sourceRef', ''),
        description = event['object'].get('description', ''),
        customFields = event['object'].get('customFields', {}))

2. Add customFields to the alert
   alert.customFields['test'] = {"string": 'Test'}

3. Update the alert. (Only the customFields)
   the_hive_api.update_alert(event['object']['id'], alert, fields=['customFields'])

4. The artifacts from the alert were deleted.

Complementary information

I have to create the alert without using 'json=', because it has file observables.
Thehive4py does not support file artifacts yet in 'json='. Even so, downloading and resending files is not efficient.