BUG/MEDIUM: str2ip: make getaddrinfo() consider local address selection policy

BUG/MEDIUM: str2ip: make getaddrinfo() consider local address selection policy

When first parameter to getaddrinfo() is not NULL (it is always not NULL
in str2ip()), on Linux AI_PASSIVE value for ai_flags is ignored. On
FreeBSD, when AI_PASSIVE is specified and hostname parameter is not NULL,
getaddrinfo() ignores local address selection policy, always returning
AAAA record. Pass zero ai_flags to behave correctly on FreeBSD, this
change should be no-op for Linux.

This fix should be backported to 1.5 as well, after some observation
period.