The Mikrotik RBM33G has only 2 LAN ports.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
[moved node in 02_network to maintain alphabetic sorting; backport]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit 3a55c793)