Clean up deployment

[ciroque]

• Remove old environment variable
• Deploy to nkl namespace

Proposed changes

There was cruft in the deployment from when the implementation could handle only one NGINX+ Edge host. That configuration has been moved into a ConfigMap, this removes the configuration from the deployment.

Also, the deployment was going into the default namespace, the deployment now uses the nkl namespace.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING document
• If applicable, I have added tests that prove my fix is effective or that my feature works
• If applicable, I have checked that any relevant tests pass after adding my changes
• I have updated any relevant documentation (README.md and CHANGELOG.md)