improve annotations/default_backend e2e test
improve annotations/default_backend e2e test

kubernetes/ingress-nginx,kubernetes/ingress-nginx,kubernetes/ingress-nginx,caicloud/ingress,canhnt/ingress,canhnt/ingress,aledbf/ingress-nginx,caicloud/ingress,caicloud/ingress,aledbf/ingress-nginx,kubernetes/ingress-nginx,canhnt/ingress,canhnt/ingress,aledbf/ingress-nginx,caicloud/ingress,aledbf/ingress-nginx,kubernetes/ingress-nginx