[gnome-system-log] build: bump libgd commit

[Cosimo Cecchi <cosimoc src gnome org>]

commit e4d097760779ef87e14c8b71c2e0b296ab79c10e
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon Jun 17 17:38:53 2013 -0700

    build: bump libgd commit

 libgd |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libgd b/libgd
index 77c6e0d..5f75e01 160000
--- a/libgd
+++ b/libgd
@@ -1 +1 @@
-Subproject commit 77c6e0dad29c244d9a353e2b86abc21552930474
+Subproject commit 5f75e01e74235e2a503356e2198599cb1105b7dc