api: traffic_control: add missing rename to 'kebab-case'

otherwise the 'delete' properties need underscores
(e.g. 'burst_in' instead of 'burst-in')

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/api2/config/traffic_control.rs

@@ -99,6 +99,7 @@ pub fn read_traffic_control(
 #[api()]
 #[derive(Serialize, Deserialize)]
 #[allow(non_camel_case_types)]
+#[serde(rename_all = "kebab-case")]
 /// Deletable property name
 pub enum DeletableProperty {
     /// Delete the rate_in property.