### Steps to reproduce

1. Disable 'Show attachments in the work packages files tab' in your project setting

2. Go to work Begin of the deletion workEnd of the deletion package list

3. Click on Begin of the insertioncreateEnd of the insertion Begin of the deletion crateEnd of the deletion and select task

4. Use the 'Upload image from computer' button in Ckeditor to upload an image

5. Save the work package


### What is the buggy behavior?

* When Saving the work package the attachment is missing in the payload of the `POST /api/v3/work_packages` instead an empty array is send:


```json
{
"subject": "Test",
"scheduleManually": true,
"startDate": null,
"dueDate": null,
"estimatedTime": null,
"duration": null,
"ignoreNonWorkingDays": false,
"percentageDone": null,
"storyPoints": null,
"_meta": {
"validateCustomFields": true
},
"customField1": null,
"customField2": null,
"customField8": null,
"customField110": null,
"customField121": {
"raw": ""
},
"_links": {
"category": {
"href": null
},
"type": {
"href": "/api/v3/types/1",
"title": "Task"
},
"priority": {
"href": "/api/v3/priorities/8",
"title": "Normal"
},
"project": {
"href": "/api/v3/projects/127",
"title": "%Complete Test"
},
"projectPhase": {
"href": null
},
"projectPhaseDefinition": {
"href": null
},
"status": {
"href": "/api/v3/statuses/1",
"title": "New"
},
"responsible": {
"href": null
},
"assignee": {
"href": null
},
"version": {
"href": null
},
"parent": {
"href": null
},
"sprint": {
"href": null
},
"customField3": {
"href": null,
"title": null
},
"customField7": {
"href": null,
"title": null
},
"customField113": {
"href": null,
"title": null
},
"self": {
"href": null
},
"attachments": [],
"fileLinks": []
},
"description": {
"raw": "<img class=\"op-uc-image op-uc-image_inline\" src=\"/api/v3/attachments/42467/content\">"
}
}
```

* The attachment gets not container when the WP is saved

* Because of the missing container the `Attachments::CleanupUncontaineredJob` will delete the attachment


### What is the expected behavior?

1. The attachment gets a container and is not deleted

<br>