Don't update certicate secret if exists to prevent multiple updates i…

…f having multiple replicas

```improvement operator
The certificate secrets stored by webhooks are no longer updated if they have not been found. This prevents that multiple pods are mutually overwritten each others freshly generated certificates and start serving an different ones.
```

pkg/webhook/certificates.go

@@ -30,7 +30,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/kubernetes/scheme"
 	"sigs.k8s.io/controller-runtime/pkg/client"
-	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 )
 
@@ -86,16 +85,14 @@ func GenerateCertificates(ctx context.Context, mgr manager.Manager, certDir, nam
 		}
 
 		secret.ObjectMeta = metav1.ObjectMeta{Namespace: namespace, Name: certSecretName}
-		if _, err := controllerutil.CreateOrUpdate(ctx, c, secret, func() error {
-			secret.Type = corev1.SecretTypeOpaque
-			secret.Data = map[string][]byte{
-				secrets.DataKeyCertificateCA: caCert.CertificatePEM,
-				secrets.DataKeyPrivateKeyCA:  caCert.PrivateKeyPEM,
-				secrets.DataKeyCertificate:   serverCert.CertificatePEM,
-				secrets.DataKeyPrivateKey:    serverCert.PrivateKeyPEM,
-			}
-			return nil
-		}); err != nil {
+		secret.Type = corev1.SecretTypeOpaque
+		secret.Data = map[string][]byte{
+			secrets.DataKeyCertificateCA: caCert.CertificatePEM,
+			secrets.DataKeyPrivateKeyCA:  caCert.PrivateKeyPEM,
+			secrets.DataKeyCertificate:   serverCert.CertificatePEM,
+			secrets.DataKeyPrivateKey:    serverCert.PrivateKeyPEM,
+		}
+		if err := c.Create(ctx, secret); err != nil {
 			return nil, err
 		}