[vala] glib-2.0: fix binding of g_variant_get_string

[Evan Nemerson <evann src gnome org>]

commit 869d07b7939bb0af866b7e56955807e0f98f1a48
Author: Ole André Vadla Ravnås <ole andre ravnas tandberg com>
Date:   Sun Apr 11 16:21:55 2010 +0200

    glib-2.0: fix binding of g_variant_get_string

 vapi/glib-2.0.vapi |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index 2df7098..b349aa1 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -3804,7 +3804,7 @@ namespace GLib {
 		public uint64 get_uint64 ();
 		public int32 get_handle ();
 		public double get_double ();
-		public unowned string get_string ();
+		public unowned string get_string (out size_t length = null);
 		public string dup_string ();
 
 		public Variant.strv (string[] value);