Don't evaluate COREDNS IP too early

[k0da]

kubectl context is not yet established during initialization. Revert
K8GB_COREDNS_IP to command to be executed rather than commands result.

Fixes #770

Signed-off-by: Dinar Valeev [email protected]

[k0da]

☸ k3d-test-gslb2 in k8gb on  make [$!?] via 🐹 v1.17.1
22:17:33 ❯ /usr/bin/make
check                     Check project integrity
demo                      Execute end-to-end demo
deploy-full-local-setup   Deploy full local multicluster setup (k3d >= 4.2.0)
deploy-gslb-operator      Deploy k8gb operator
deploy-test-apps          Deploy Podinfo (example app) and Apply Gslb Custom Resources
deploy-test-version       Upgrade k8gb to the test version on existing clusters
destroy-full-local-setup  Destroy full local multicluster setup
dns-tools                 Run temporary dnstools pod for debugging DNS issues
help                      Show this help

☸ k3d-test-gslb2 in k8gb on  make [$!?] via 🐹 v1.17.1
22:17:38 ❯ make test-round-robin
{
  "hostname": "frontend-podinfo-7579d54897-pl96f",
  "version": "5.1.1",
  "revision": "",
  "color": "#34577c",
  "logo": "https://raw.githubusercontent.com/stefanprodan/podinfo/gh-pages/cuddle_clap.gif",
  "message": "us",
  "goos": "linux",
  "goarch": "amd64",
  "runtime": "go1.15.6",
  "num_goroutine": "8",
  "num_cpu": "6"
}pod "busybox" deleted

[somaritane]

lgtm!