Fixing ptree to only compile when madness is enabled so serial builds don't fail without madness.
Fixing ptree to only compile when madness is enabled so serial builds don't fail without madness.

tdgoodrich/inddgo_pure,tdgoodrich/inddgo_pure,tdgoodrich/inddgo_pure,tdgoodrich/inddgo_pure,tdgoodrich/inddgo_pure