[vala/0.36] gio-2.0: Result of DBusMessage.get_header() is unowned

[Rico Tzschichholz <ricotz src gnome org>]

commit 285996b0034f81a92f3200efc3c673d807b326d1
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Nov 7 12:15:25 2018 +0100

    gio-2.0: Result of DBusMessage.get_header() is unowned

 vapi/gio-2.0.vapi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/vapi/gio-2.0.vapi b/vapi/gio-2.0.vapi
index 44d7a3d72..12d49a996 100644
--- a/vapi/gio-2.0.vapi
+++ b/vapi/gio-2.0.vapi
@@ -772,7 +772,7 @@ namespace GLib {
                public unowned string get_destination ();
                public unowned string get_error_name ();
                public GLib.DBusMessageFlags get_flags ();
-               public GLib.Variant get_header (GLib.DBusMessageHeaderField header_field);
+               public unowned GLib.Variant? get_header (GLib.DBusMessageHeaderField header_field);
                [CCode (array_length = false, array_null_terminated = true)]
                public uchar[] get_header_fields ();
                public unowned string get_interface ();