BIO_lookup_ex: use AI_ADDRCONFIG only if explicit host name is given
The flag only affects which record types are queried via DNS (A or
AAAA, or both). When node is NULL and AF_UNSPEC is used, it prevents
getaddrinfo returning the right address associated with the loopback
interface.
Signed-off-by: Daiki Ueno <dueno@redhat.com> Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/16033)