Push to insecure registry fails when using Kaniko build strategy

[orpiske]

This is similar to the issue I reported on #2122, but involves one more item.

In addition to the items reported on the aforementioned issue, the push also fails because Kaniko itself assumes https. A simple work-around for this is setting the flags --skip-tls-verify and --skip-tls-verify-pull. They force Kaniko to use the HTTP protocol when talking to the registry.

DEBU[0000] Copying file /builder/kit-c17mger67bimpfkia980/context/Dockerfile to /kaniko/Dockerfile 
error checking push permissions -- make sure you entered the correct tag name, and that you are authenticated correctly, and try again: checking push permission for "my-insecure-registry-with-no-https.com/opiske/camel-k-kit-c17mger67bimpfkia980:380084": creating push check transport for k3s-node-master.usersys.redhat.com failed: Get https://my-insecure-registry-with-no-https.com/v2/: x509: certificate has expired or is not yet valid

I have a fix in place and will open a PR with a proposed fix soon.

[astefanutti]

Fixes with #2130. Thanks!