Webhook on create/delete branch not working as expected

Hi there,

I have a problem with the webhooks of a project. Sometimes there is no payload in the post-message from gitlab, when I create or delete a branch remotely via git (e.g. git push origin --delete branchname).
I use the example webhook receiver for testing and created a webhook for a project in gitlab to send messages to the testreceiver. Sometimes there is a payload and the message form gitlab and the receiver shows a POST with JSON:

{JSON here}
Content-Type: application/json
X-Gitlab-Event: Push Hook
Connection: close
Content-Length: 2083

"POST / HTTP/1.1" 200 0

The JSON contains a before or after of 0s, as described in the documentation.
But often the message doesn’t contain anything and the receiver only prints:

"POST / HTTP/1.1" 200 0

Normal commits work fine.

Has anyone an idea, why there is no payload in the messages? GitLab is version 10.1.1.

Kind regards,