Backport of commit 60a13b98e9f410c3b1019252f271d3c0f20b2e61 for 2.12.20

From 60a13b98e9f410c3b1019252f271d3c0f20b2e61 Mon Sep 17 00:00:00 2001
From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
Date: Fri, 23 Sep 2011 14:39:29 +0000
Subject: a hack to allow compilation on systems without AF_LOCAL.

--- lib/nettle/egd.c
+++ lib/nettle/egd.c
@@ -33,6 +33,12 @@
 
 #include <gnutls_errors.h>
 
+#ifdef AF_UNIX
+# define LOCAL_SOCKET_TYPE AF_UNIX
+#else
+# define LOCAL_SOCKET_TYPE AF_LOCAL
+#endif
+
 #ifndef offsetof
 #define offsetof(type, member) ((size_t) &((type *)0)->member)
 #endif
@@ -141,12 +147,12 @@
     }
 
   memset (&addr, 0, sizeof addr);
-  addr.sun_family = AF_LOCAL;
+  addr.sun_family = LOCAL_SOCKET_TYPE;
   strcpy (addr.sun_path, name);
   addr_len = (offsetof (struct sockaddr_un, sun_path)
               + strlen (addr.sun_path));
 
-  fd = socket (AF_LOCAL, SOCK_STREAM, 0);
+  fd = socket (LOCAL_SOCKET_TYPE, SOCK_STREAM, 0);
   if (fd == -1)
     {
       _gnutls_debug_log ("can't create unix domain socket: %s\n",