ISC libbind provides AI_ADDRCONFIG macro, but getaddrinfo() fails with
EAI_BADFLAGS when invoked with it.  This patch retries getaddrinfo()
without AI_ADDRCONFIG flag in this case.

It is very simple and a ./configure test for working AI_ADDRCONFIG
might be better.

Index: milter-greylist-4.4.1/spamd.c
===================================================================
--- milter-greylist-4.4.1.orig/spamd.c
+++ milter-greylist-4.4.1/spamd.c
@@ -470,11 +470,21 @@ spamd_inet_socket(host, port)
 
 	bzero(&hints, sizeof(hints));
 	hints.ai_socktype = SOCK_STREAM;
+
 #ifdef AI_ADDRCONFIG
 	hints.ai_flags = AI_ADDRCONFIG;
+
+again:
+	e = getaddrinfo(host, port, &hints, &ai);
+	if (e == EAI_BADFLAGS && (hints.ai_flags & AI_ADDRCONFIG)) {
+		hints.ai_flags &= ~AI_ADDRCONFIG;
+		goto again;
+	}
+#else
+	e = getaddrinfo(host, port, &hints, &ai);
 #endif
 
-	if ((e = getaddrinfo(host, port, &hints, &ai))) {
+	if (e) {
 		mg_log(LOG_ERR, 
 		       "spamd getaddrinfo failed: %s", 
 		       gai_strerror(e));