[simple-scan/gnome-3-12: 4/13] Stop configure if vala not found

[Robert Ancell <rancell src gnome org>]

commit 91ee1ada52293b7be7161f0cf7108548a6181e4d
Author: Robert Ancell <robert ancell canonical com>
Date:   Fri Aug 29 13:58:20 2014 +1200

    Stop configure if vala not found

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index ea7c584..3edadff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,7 @@ AM_SILENT_RULES([yes])
 AM_MAINTAINER_MODE
 GNOME_MAINTAINER_MODE_DEFINES
 
-AM_PROG_VALAC([0.16.0])
+AM_PROG_VALAC([0.16.0], [], [AC_MSG_ERROR([Vala compiler not found])])
 AM_PROG_CC_C_O
 
 GLIB_GSETTINGS