[ghex] Include ui.h as it's needed, fixes bug 597684.

[Andre Klapper <aklapper src gnome org>]

commit 3217be7e08d74e8da9019a1131bccb2a54a402df
Author: Tobias Mueller <tobiasmue gnome org>
Date:   Wed Jan 27 20:47:45 2010 +0100

    Include ui.h as it's needed, fixes bug 597684.

 src/preferences.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/preferences.c b/src/preferences.c
index e694ee7..622d039 100644
--- a/src/preferences.c
+++ b/src/preferences.c
@@ -33,6 +33,7 @@
 #include "preferences.h"
 #include "configuration.h"
 #include "ghex-window.h"
+#include "ui.h"
 
 #define MAX_MAX_UNDO_DEPTH 100000