[gnome-desktop] thumbnail: Fix a compile-time warning

[Bastien Nocera <hadess src gnome org>]

commit 9d8c51bc5d8046e062509300f1e1015cc4d26c78
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jan 16 15:56:30 2018 +0100

    thumbnail: Fix a compile-time warning
    
    gnome-desktop/libgnome-desktop/gnome-desktop-thumbnail-script.c: In function ‘child_setup’:
    gnome-desktop/libgnome-desktop/gnome-desktop-thumbnail-script.c:650:17: warning: comparison between 
signed and unsigned integer expressions [-Wsign-compare]
       for (i = 0; i < fd_array->len; i++)
                     ^

 libgnome-desktop/gnome-desktop-thumbnail-script.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libgnome-desktop/gnome-desktop-thumbnail-script.c 
b/libgnome-desktop/gnome-desktop-thumbnail-script.c
index 4fed111..960c639 100644
--- a/libgnome-desktop/gnome-desktop-thumbnail-script.c
+++ b/libgnome-desktop/gnome-desktop-thumbnail-script.c
@@ -640,7 +640,7 @@ static void
 child_setup (gpointer user_data)
 {
   GArray *fd_array = user_data;
-  int i;
+  guint i;
 
   /* If no fd_array was specified, don't care. */
   if (fd_array == NULL)