mod_instantiate instance variable 2.2.4 vs 3.0.9

[Richard Levenberg]

In converting my module development efforts from 2.2.4 to 3.0.9 to make
use of the v3, "session-state" I noticed a difference in mod_instantiate
where the instance variable is passed as *instance rather than
**instance. I don't need to keep around any of the configuration
information, I only use it to get a pointer into a library object that I
can subsequently use with mod_authorize and mod_authenticate.

So in 3.0.9 is it just assumed that you will carry around config via the
instance variable that you don't need. I see in rlm_example.c the comment: "
 *	If configuration information is given in the config section
 *	that must be referenced in later calls, store a handle to it
 *	in *instance otherwise put a null pointer there.
"

But I'm not clear what that comment means nor how to reset the instance
variable pointer to the actual thing I need to keep around.

r