upstream: Revert previous two commits

It turns out we still support pre-auth compression on the client.
Therefore revert the previous two commits:

date: 2018/07/06 09:06:14;  author: sf;  commitid: yZVYKIRtUZWD9CmE;
 Rename COMP_DELAYED to COMP_ZLIB

 Only delayed compression is supported nowadays.

 ok markus@

date: 2018/07/06 09:05:01;  author: sf;  commitid: rEGuT5UgI9f6kddP;
 Remove leftovers from pre-authentication compression

 Support for this has been removed in 2016.
 COMP_DELAYED will be renamed in a later commit.

 ok markus@

OpenBSD-Commit-ID: cdfef526357e4e1483c86cf599491b2dafb77772
diff --git a/kex.h b/kex.h
index b57f985..e381604 100644
--- a/kex.h
+++ b/kex.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.h,v 1.87 2018/07/06 09:06:14 sf Exp $ */
+/* $OpenBSD: kex.h,v 1.88 2018/07/09 13:37:10 sf Exp $ */
 
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
@@ -65,6 +65,7 @@
 
 #define COMP_NONE	0
 #define COMP_ZLIB	1
+#define COMP_DELAYED	2
 
 #define CURVE25519_SIZE 32