[vala] glib: make the parameter of VariantDict constructor nullable

[Luca Bruno <lucabru src gnome org>]

commit 198d7e8bbaabe405c7096de4d6de0bc5c68fe6fd
Author: XZS <d f fischer web de>
Date:   Mon Aug 11 14:33:32 2014 +0200

    glib: make the parameter of VariantDict constructor nullable
    
    The underlying glib implementation accepts null to initialize an empty
    dictionary. The vapi now reflects this, defaulting the single parameter
    to null.
    
    Fixes bug 734612

 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 272a1ad..13ae5e2 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -5043,7 +5043,7 @@ namespace GLib {
 
        [Compact, CCode (ref_function = "g_variant_dict_ref", unref_function = "g_variant_dict_unref")]
        public class VariantDict {
-               public VariantDict (GLib.Variant from_asv);
+               public VariantDict (GLib.Variant? from_asv = null);
                public bool lookup (string key, string format_string, ...);
                public GLib.Variant lookup_value (string key, GLib.VariantType expected_type);
                public bool contains (string key);