[gnome-system-monitor] Updated call to deprecated librsvg function.

[Robert Roth <robertroth src gnome org>]

commit bc12918860d574c32a18b963107d37035625bbaf
Author: Robert Roth <robert roth off gmail com>
Date:   Sat Jan 28 06:56:48 2012 +0200

    Updated call to deprecated librsvg function.

 src/gsm_color_button.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/gsm_color_button.c b/src/gsm_color_button.c
index 8cc2ce6..c1b1383 100644
--- a/src/gsm_color_button.c
+++ b/src/gsm_color_button.c
@@ -261,7 +261,7 @@ fill_image_buffer_from_file (cairo_t *cr, const char *filePath)
   tmp_cr = cairo_create (tmp_surface);
   rsvg_handle_render_cairo (handle, tmp_cr);
   cairo_destroy (tmp_cr);
-  rsvg_handle_free (handle);
+  g_object_unref (handle);
   return tmp_surface;
 }