Update A Webhook For A Repository

Updates the specified webhook subscription.The following properties can be mutated:* `description`* `url`* `secret`* `active`* `events`The hook's secret is used as a key to generate the HMAC hex digest sent in the`X-Hub-Signature` header at delivery time. This signature is only generatedwhen the hook has a secret.Set the hook's secret by passing the new value in the `secret` field. Passing a`null` value in the `secret` field will rem...