Wrong error message when creating a observable with invalid data

[To-om]

Request Type

Bug

Work Environment

Question	Answer
OS version (server)	Ubuntu
OS version (client)	Ubuntu, ...
TheHive version / git hash	<= 3.0.9
Package Type	DEB
Browser type & version	If applicable

Problem Description

When one tries to create an observable with invalid data (TLP=4 for example), TheHive says that the observable already exists (even if it doesn't exist).

Steps to Reproduce

$ curl -s \
  -H 'Authorization: bearer ** API KEY **' \
  -H 'Content-type: application/json' \
  http://127.0.0.1:9000/api/case/AWMlW5wS695cfl3hKzHL/artifact \
  -d '{"data":"127.0.0.1","dataType":"ip","tlp":4,"message":"localhost"}'

returns

{
  "type": "ConflictError",
  "message": "Artifact already exists",
  "object": {
    "data": "127.0.0.1",
    "dataType": "ip",
    "tlp": 10,
    "message": "localhost"
  }
}