[calls] message-source: Clean up includes

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 7d05508ace8192a546c34854cad3305f78ddb821
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Mon Dec 27 20:11:50 2021 +0100

    message-source: Clean up includes
    
    Include directly what's being used here.

 src/calls-message-source.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/src/calls-message-source.h b/src/calls-message-source.h
index 844ec60f..4763bd5c 100644
--- a/src/calls-message-source.h
+++ b/src/calls-message-source.h
@@ -24,9 +24,7 @@
 
 #pragma once
 
-#include "util.h"
-
-#include <glib-object.h>
+#include <gtk/gtk.h>
 
 G_BEGIN_DECLS