[gcalctool] Drop obsolete include

[Robert Ancell <rancell src gnome org>]

commit fd804a8f91782bc801284eb327745e15badce4d5
Author: Robert Ancell <robert ancell canonical com>
Date:   Wed Dec 22 09:36:47 2010 +1100

    Drop obsolete include

 src/math-buttons.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/src/math-buttons.c b/src/math-buttons.c
index a9fd10f..8eaad4d 100644
--- a/src/math-buttons.c
+++ b/src/math-buttons.c
@@ -23,7 +23,6 @@
 #include "financial.h"
 #include "currency.h"
 #include "mp-serializer.h"
-#include "units.h"
 
 enum {
     PROP_0,