Don't forget to initialise ret->ai to NULL in sk_nonamelookup. Was

causing segfaults in IPv6-enabled Unix PuTTY connecting through a
proxy when letting the proxy do the DNS.

[originally from svn r5064]

unix/uxnet.c

@@ -209,6 +209,9 @@ SockAddr sk_nonamelookup(const char *host)
     ret->family = AF_UNSPEC;
     strncpy(ret->hostname, host, lenof(ret->hostname));
     ret->hostname[lenof(ret->hostname)-1] = '\0';
+#ifndef NO_IPV6
+    ret->ai = NULL;
+#endif
     return ret;
 }