This hook is called to see whether the Pengine must be executed in a
protected environment. It is only called after authentication_hook/3
has confirmed the authentity of the current user. If this hook
succeeds, both loading the code and executing the query is executed
without enforcing sandbox security. Typically, one should:
Provide a safe user authentication hook.
Enable HTTPS in the server or put it behind an HTTPS proxy and
ensure that the network between the proxy and the pengine
server can be trusted.