Trigger with Webhook not working since Updated 12.0.0

Summary

Webhook Trigger not working since updated to 12.0.0

Steps to reproduce

• Define a CI/CD Trigger with Project Settings -> CI / CD -> Pipeline Triggers -> add Trigger
• call the new Trigger with displayed Webhook Command like: http://gitlab.example.com/api/v4/projects/PROJECT_ID/ref/REF_NAME/trigger/pipeline?token=TOKEN
• Result is: {"error":"404 Not Found"}
• the same trigger is working from other gitlab pipeline with the curl command: curl -X POST -F token=TOKEN -F ref=REF_NAME http://gitlab.example.com/api/v4/projects/PROJECT_ID/trigger/pipeline
• the same trigger worked before we have updated to 12.0.0

We need to call the Webhook URL. It is not a possible solution or a workaround to call the extended curl command.