Update unit to unit recording config documentation.

[tadscottsmith]

When I wrote the documentation for the recordUUVCalls config option, I mistakenly put it in the system object level versus the global level. At some point, I think the config option belongs at the system level, but until the code reflects that, this should update the documentation to be accurate.

[robotastic]

Good catch and a good point. It should probably be defined per system vs globally. I wonder how often this feature is even used though...