Fix build error under FreeBSD 5.3. EAI_NODATA is not defined.

Okay'd by maintainer, Otto H.
Tested under NetBSD 1.6.2 and FreebSD 5.3.
(I later saw same fix in irssi CVS.)
This will close PR pkg/28534.

chat/irssi/distinfo

@@ -1,7 +1,8 @@
-$NetBSD: distinfo,v 1.17 2005/02/23 15:59:12 agc Exp $
+$NetBSD: distinfo,v 1.18 2005/03/20 05:05:59 reed Exp $
 
 SHA1 (irssi-0.8.9.tar.bz2) = 57799a1e99ac5f6694eb6fd049d39a4e2e51f576
 RMD160 (irssi-0.8.9.tar.bz2) = 7a0a2a639c041802bfddd458c35bccaec8084013
 Size (irssi-0.8.9.tar.bz2) = 816465 bytes
 SHA1 (patch-aa) = 45d8161733f58ab3733022c823933bb1cc93a8e2
 SHA1 (patch-ab) = c395fbeeb2dd15490f04f2cb2c94daf6c5955e85
+SHA1 (patch-ac) = 9572891333279dc368f44c52f9584c34f10d7aa1

chat/irssi/patches/patch-ac

@@ -0,0 +1,16 @@
+$NetBSD: patch-ac,v 1.6 2005/03/20 05:05:59 reed Exp $
+
+--- src/core/network.c.orig	Wed Mar 16 20:01:11 2005
++++ src/core/network.c	Wed Mar 16 20:03:31 2005
+@@ -607,7 +607,11 @@
+ int net_hosterror_notfound(int error)
+ {
+ #ifdef HAVE_IPV6
++#ifdef EAI_NODATA
+ 	return error != 1 && (error == EAI_NONAME || error == EAI_NODATA);
++#else
++	return error != 1 && (error == EAI_NONAME);
++#endif
+ #else
+ 	return error == HOST_NOT_FOUND || error == NO_ADDRESS;
+ #endif