doc: Update substitute server.

Fixes an accidental revert in commit
0a5fa004f7f21dc3e01747b8e94fbb21e056e4ca.

* doc/guix.texi (SUBSTITUTE-SERVER): Really change to ci.guix.info.

diff --git a/doc/guix.texi b/doc/guix.texi
index c138d43..a08a999 100644 (file)
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -14,7 +14,7 @@
 @set KEY-SERVER pool.sks-keyservers.net
 
 @c The official substitute server used by default.
-@set SUBSTITUTE-SERVER mirror.hydra.gnu.org
+@set SUBSTITUTE-SERVER ci.guix.info
 
 @copying
 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*