Jump from the 3.x series to 4.x, which tracks libyang 5.x and moves its
SONAME from libnetconf2.so.3 to libnetconf2.so.5.
Switch DEPENDS back to +libyang and drop the legacy staging prefix
override. ENABLE_PAM=OFF is upstream now, so its patch goes away.
4.x owns the transport YANG modules netopeer2 registers at first boot,
so ship them to /etc/netconf2/modules.
Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>
