fix build on 5-CURRENT after RFC3542 change (EAI_ADDRFAMILY and
EAI_NODATA were obsoleted).
There is some issue; we have EAI_NODATA as an alias of EAI_NONAME
for workaround. However, some of these ports use it as a case
label of switch. Since our alias broke such code, we may better
to consider deleting such alias.
Requested by: kris
Approved by: portmgr (kris) (implicitly)