C++: fix Set implementation
C++: fix Set implementation

Signed-off-by: Matija Amidzic <98dfd892fab0e2bddda987622ee1038e8a1aff95@sartura.hr>

PavolVican/libyang,PavolVican/libyang,PavolVican/libyang,PavolVican/libyang,PavolVican/libyang