Put Lazybones' Proxy in config.groovy

Lazybones documents a system-property configuration mechanism from version 0.8.1. In the user's ~/.lazybones/config.groovy, the proxy entries can be written as:

systemProp {
    http {
        proxyHost = 'proxy.example'
        proxyPort = 8080
    }
    https {
        proxyHost = 'proxy.example'
        proxyPort = 8080
    }
}

The systemProp prefix turns these entries into the corresponding JVM system properties inside Lazybones. The HTTP and HTTPS groups describe destination protocols and can use the same proxy endpoint. For a public template download permitted through an unauthenticated intermediary, choose an HTTP entry from the HTTP proxy list for those endpoint values.

Add this block to the existing configuration, preserving template mappings and other options. Start the Lazybones command with the intended user configuration in place. This public mechanism avoids maintaining a separate proxy edit inside a generated or installed launcher.