[aisleriot] build: Mark GUILE_TOOLS variable as precious

[Christian Persch <chpe src gnome org>]

commit 9c06eb530c62a1fa59972de877ba6da2f2a3b190
Author: Christian Persch <chpe gnome org>
Date:   Tue Nov 29 17:41:24 2011 +0100

    build: Mark GUILE_TOOLS variable as precious

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9099bf0..0b6da51 100644
--- a/configure.ac
+++ b/configure.ac
@@ -570,6 +570,7 @@ PKG_CHECK_MODULES([GUILE],[$GUILE_PKGS])
 
 AM_CONDITIONAL([HAVE_GUILE_2_X],[test "$with_guile" != "1.8"])
 
+AC_ARG_VAR([GUILE_TOOLS])
 AC_PATH_PROG([GUILE_TOOLS],[guile-tools],[false])
 if test "$GUILE_TOOLS" = "false"; then
   AC_MSG_ERROR([guile-tools not found])