Fix Control Ingress Creation

[alfredopalhares]

By default if you enable ingress for the control api the chart breaks, its checking bad place for the servicePort.

This fixes that, and add tests with helm- unittest, it currently only tests this exact situation, since i dont know if its something that the maintainers want. I can add more unitttest if you want.

Regards,
Alfredo Palhares

[kzmain]

Hi alfredopalhares, may I ask does our control api work well after you updated the code? I did the same fix as yours, and it shows 404 error per screenshot shows.
The helm command that I start the servies is:

helm repo add apisix https://charts.apiseven.com
helm repo update
helm upgrade --install apisix . \
--create-namespace --namespace apisix \
--set ingress.enabled=true \
--set ingress.className=nginx \
--set "ingress.hosts[0].host=apisix\.local" \
--set "ingress.hosts[0].paths[0]=\/" \
--set apisix.admin.enabled=true \
--set apisix.admin.ingress.enabled=true \
--set apisix.admin.ingress.className=nginx \
--set control.enabled=true \
--set control.ingress.enabled=true \
--set control.ingress.className=nginx \
--set ingress-controller.enabled=true \
--set ingress-controller.config.apisix.serviceNamespace=apisix