sockstat: change check for wildcard sockets to avoid historical classes

sockstat was checking whether a bound address was "host 0", the lowest
host on a network, using inet_lnaof(). This only works for class A/B/C.
However, it isn't useful to bind such an address unless it is really
the unspecified address INADDR_ANY. Change the check to to use that.

(cherry picked from commit 64acb29b7d9699c301a55a5431d94374391e4f30)