[gnome-control-center] build: Add missing variable setting

[Bastien Nocera <hadess src gnome org>]

commit edbae67a9a751256aa2e4e5a6e62368f1d8c208d
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Apr 16 11:03:37 2014 +0200

    build: Add missing variable setting
    
    We weren't setting have_wacom anymore after the changes in
    edf60cdd3b11c45d0437515b72d56176bc1855ad.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 28480e2..c831e0d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -298,6 +298,7 @@ case $host_os in
                         gnome-desktop-3.0 >= $GNOME_DESKTOP_REQUIRED_VERSION
                         clutter-gtk-1.0
                         clutter-1.0 >= $CLUTTER_REQUIRED_VERSION)
+      have_wacom=yes
       AC_DEFINE(BUILD_WACOM, 1, [Define to 1 to build the Wacom panel])
       AC_DEFINE(HAVE_WACOM, 1, [Define to 1 is Wacom is supportted])
     fi