data tree OPTIMIZE unlinking the last node (child)
data tree OPTIMIZE unlinking the last node (child)

In case the node has a parent, use it to locate the first node
in the siblings list to update its "last" pointer.

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