Removed some extraneous debugging output. Hey, this one was subtle. Due

Removed some extraneous debugging output.  Hey, this one was subtle.  Due
to const/no-const variants of the prop->getNode() method, the 2nd bool
argument was getting promoted to an int so it would match a method with
a const SGPropertyNode * as the first argument.  But that made
it match the wrong version of prop->getNode() and things were failing.
Yikes!  This is one I could have stared at for days to figure out so I'm
glad I caught on to the problem. :-)