Allow for default open on gatekeeper

[filippomc]

The gatekeeper by default is set in "default-deny" mode.
This is to allow for a default white listed option.

One way to achieve this would be to use a ternary logic on the secured attribute:

harness:
  secured: "open"

[filippomc]

Note that cannot simply do

- uri: /*
  white-listed: true

As cannot white list everything with default deny option enabled

The gatekeeper fails with:

2022-08-29T14:49:20.010Z        info    starting the service    {"prog": "gatekeeper", "author": "go-gatekeeper", "version": "1.3.8 (git+sha: 499bcbe-dirty, built: 09-01-2022)"}
2022-08-29T14:49:20.010Z        info    attempting to retrieve configuration discovery url      {"url": "http://accounts.areg.local/auth/realms/areg", "timeout": "30s"}
2022-08-29T14:49:20.022Z        info    successfully retrieved openid configuration from the discovery
2022-08-29T14:49:20.022Z        info    enabled reverse proxy mode, upstream url        {"url": "http://areg-portal.areg:8080/"}
2022-08-29T14:49:20.022Z        info    enabled health service  {"path": "/oauth/health"}
2022-08-29T14:49:20.022Z        info    using session cookies only for access and refresh tokens
2022-08-29T14:49:20.022Z        info    loading the custom templates    {"templates": "/templates/access-denied.html.tmpl"}
2022-08-29T14:49:20.023Z        warn    the resource url is not a prefix        {"resource": "/", "change": "/", "amended": ""}
[error] you've asked for a default denial but whitelisted everything