Pass NI_NUMERICSERV|NI_NUMERICSCOPE if NI_NUMERICHOST to getnameinfo.

This addresses part of https://github.com/heimdal/heimdal/issues/1214
to audit potential network leaks with [libdefaults] block_dns = yes.

NI_NUMERICHOST is _probably_ sufficient -- we probably won't see many
systems using NIS to look up service names by number if we fail to
specify NI_NUMERICSERV, and such systems probably require careful
auditing of their own.  And I don't know of any way NI_NUMERICSCOPE
could trigger network leaks.  But named scope ids are such a niche
option with IPv6 that setting it to forestall concerns can't hurt
much, and it makes reviewing easier if we just unconditionally flip
on all the numeric-only options.

lib/krb5/krbhst.c

@@ -656,7 +656,7 @@ add_locate(void *ctx, int type, struct sockaddr *addr)
     portnum = socket_get_port(addr);
 
     ret = getnameinfo(addr, socklen, host, sizeof(host), port, sizeof(port),
-		      NI_NUMERICHOST|NI_NUMERICSERV);
+		      NI_NUMERICHOST|NI_NUMERICSERV|NI_NUMERICSCOPE);
     if (ret != 0)
 	return 0;