Don't crash if class_info() is called on non-luabind objects.
Don't crash if class_info() is called on non-luabind objects.

Oberon00/luabind,Kazade/luabind-deboostified,MrApplejuice/luabind,alex85k/luabind,mdave88/luabind,luabind/luabind,rpavlik/luabind,alex85k/luabind,luabind/luabind,grafi-tt/luabind,mapbox/luabind,rpavlik/luabind,plsytj/luabind,Oberon00/luabind,galek/luabind-deboostified,alex85k/luabind,lonski/luabind,rpavlik/luabind,davidar/luabind,luabind/luabind,decimad/luabind-deboostified,rpavlik/luabind,alex85k/luabind,ltjax/luabind-deboostified,luabind/luabind,Wohlhabend-Networks/luabind-deboostified,rpavlik/luabind