Panic: slice bounds out of range under arm64 because of old dependency pkg

[4nx]

Describe the bug:
I started to create a new webhook for another DNS provider. You can find it here: github.com/4nx/cert-manager-webook-joker. While building and testing the package under arm64 I found a bug within an old dependency package which is used.

TEST_ZONE_NAME=xxx go test .
panic: runtime error: slice bounds out of range [:9] with length 8

goroutine 1 [running]:
github.com/miekg/dns.ClientConfigFromFile(0x1346942, 0x10, 0x0, 0x0, 0x0)
	/home/ubuntu/go/pkg/mod/github.com/miekg/dns@v0.0.0-20170721150254-0f3adef2e220/clientconfig.go:86 +0x8b4
github.com/jetstack/cert-manager/pkg/issuer/acme/dns/util.getNameservers(0x1346942, 0x10, 0x229a540, 0x2, 0x2, 0x0, 0x25, 0x21ba808)
	/home/ubuntu/go/pkg/mod/github.com/jetstack/cert-manager@v0.13.1/pkg/issuer/acme/dns/util/wait.go:51 +0x30
github.com/jetstack/cert-manager/pkg/issuer/acme/dns/util.init()
	/home/ubuntu/go/pkg/mod/github.com/jetstack/cert-manager@v0.13.1/pkg/issuer/acme/dns/util/wait.go:44 +0x88
FAIL	github.com/4nx/cert-manager-webhook-joker	0.122s
FAIL

The problem is that a very old version of github.com/miekg/dns package is still used:

https://github.com/jetstack/cert-manager-webhook-example/blob/7a722fd8517afee606f0c13673880f6eedee5d87/go.sum#L294

The project had a bug until version 1.0.4:

https://github.com/miekg/dns/blob/5364553f1ee9cddc7ac8b62dce148309c386695b/clientconfig.go#L94

which had been fixed in version 1.0.5 after this pull request miekg/dns#642 through:

miekg/dns@0079071

The most recent version of the project is 1.1.35.

Expected behaviour:
A working webhook under ARM64.

Steps to reproduce the bug:
Simply following: https://github.com/4nx/cert-manager-webhook-joker#development under ARM64

Anything else we need to know?:
The webhook is working under amd64.

Environment details::

• Kubernetes version: v1.20.0+k3s2
• Cloud-provider/provisioner: K3s under raspberry pi 4
• cert-manager version: v.1.1.0
• Install method: helm

/kind bug

[4nx]

I added a pull request to fix the bug only by updating the miekg/dns packages just a bit.

[4nx]

#19