doc: Remove stale reference to 'hydra.gnu.org'.version-0.16.0

Reported by Thomas Schmitt <scdbackup@gmx.net>.

* doc/guix.texi (Binary Installation): Refer to SUBSTITUTE-SERVER, not
to 'hydra.gnu.org'.

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 4ef2601579a..774fbd96471 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -585,12 +585,12 @@ Info search path.)
 
 @item
 @cindex substitutes, authorization thereof
-To use substitutes from @code{hydra.gnu.org} or one of its mirrors
+To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
 (@pxref{Substitutes}), authorize them:
 
 @example
 # guix archive --authorize < \
-     ~root/.config/guix/current/share/guix/hydra.gnu.org.pub
+     ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
 @end example
 
 @item