[gtksourceview] Try harder to fix the #include for Windows

[Sébastien Wilmet <swilmet src gnome org>]

commit 39e66445a96181c27f3a5d833fc72aa252ec3f5b
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon Dec 5 20:22:36 2016 +0100

    Try harder to fix the #include for Windows
    
    See the discussion at:
    https://bugzilla.gnome.org/show_bug.cgi?id=774325

 gtksourceview/gtksourceview-init.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtksourceview/gtksourceview-init.c b/gtksourceview/gtksourceview-init.c
index e285d47..02d596f 100644
--- a/gtksourceview/gtksourceview-init.c
+++ b/gtksourceview/gtksourceview-init.c
@@ -37,7 +37,8 @@
 #include "gtksourcestyleschememanager.h"
 
 #ifdef G_OS_WIN32
-#include <windef.h>
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
 
 static HMODULE gtksourceview_dll;
 #endif