Incorrect condition for error logging for webhook sink

[sbrakl]

When using webhook to export Kubernetes event, if the webhook return 200, it logs it as error "not 200/201". Log severity is debug,error. This is due to incorrect condition at

pkg/sinks/webhook.go line 56

Condition should be treat all http status between [200-204] as success

if resp.StatusCode > 204 { 
...
}