Evaluate the api_fqdn outside of the variables template callback

I think there is a bug in the `shell-config.yml`.

In my case,  I override the `node['gitlab']['web_fqdn']` in a wrapper cookbook, but I found out that doing that expands `@fqdn` in the shell-config.yml as 'true'. 

```
gitlab_url: "http://true:80/" 
```
I think we should evaluate it outside of the variables callback, as the `@listen`.