Remove NO_IPPORT_RESERVED_CONCEPT

Replace by defining IPPORT_RESERVED to zero on Cygwin, which should have
the same effect without causing problems syncing patches with OpenBSD.
Resync the two affected functions with OpenBSD.  ok djm, sanity checked
by Corinna.
diff --git a/serverloop.c b/serverloop.c
index f9e3e5d..3563e5d 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1243,12 +1243,9 @@
 		/* check permissions */
 		if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
 		    no_port_forwarding_flag ||
-		    (!want_reply && fwd.listen_port == 0)
-#ifndef NO_IPPORT_RESERVED_CONCEPT
-		    || (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED &&
-		    pw->pw_uid != 0)
-#endif
-		    ) {
+		    (!want_reply && fwd.listen_port == 0) ||
+		    (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED &&
+		    pw->pw_uid != 0)) {
 			success = 0;
 			packet_send_debug("Server has disabled port forwarding.");
 		} else {