Plugins » Discovery

We should be able to render proxy.url for each particular TFTP proxy we deploy on, so users won't need to setup this manually anymore when enabling discovery plugin:

- if the proxy has discovery feature turned on, use: proxy.type=proxy proxy.url=smart_proxy_url
- otherwise use proxy.type=foreman proxy.url=foreman_url

For this to work, we need to propagate proxy object into the default template when rendering it.