JSON printer BUGFIX accessing child member in leaf-list data structure that does not have this member
JSON printer BUGFIX accessing child member in leaf-list data structure that does not have this member

Because there is a common function for list and leaf-list, the members that
are not common for the both data structures must be accessed more carefully.

Fixes #121

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