Partial update for a printer.

connection_type is deliberately absent. POS-103 requires a change of
transport to go back through the pairing wizard rather than being a silent
in-place edit: a printer re-addressed from LAN to Bluetooth has different
reachability, different discovery and a different test-print result, and
nothing here could verify the new transport works. Re-pairing is
delete-and-add, which forces the wizard's test print.

address and port ARE editable — a DHCP lease moving a printer to a
new IP is the single most common real-world repair, and forcing a re-pair
for it would mean re-entering a name and location that did not change.