Clear empty chat throws 500

# Steps

1. Create an item
2. Go to settings
3. Clear Chat

Expected behavior: either button is disabled because there's no message, or the result is OK.
Current behavior: We receive error 500:

```
{
"statusCode": 500,
"error": "Internal Server Error",
"message": "The deletion of a new ChatMessage failed, the entry was not found."
}
```