[vala] glib-2.0: Update "g_utf8_make_valid" binding

[Rico Tzschichholz <ricotz src gnome org>]

commit 6d27ce19382bdb1d14c46cd33144c28a68ffcf38
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Mar 5 19:57:41 2017 +0100

    glib-2.0: Update "g_utf8_make_valid" binding

 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 9b57dea..3dc320d 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -1192,7 +1192,7 @@ public class string {
        public bool validate (ssize_t max_len = -1, out char* end = null);
        [Version (since = "2.52")]
        [CCode (cname = "g_utf8_make_valid")]
-       public string make_valid ();
+       public string make_valid (ssize_t len = -1);
        [CCode (cname = "g_utf8_normalize")]
        public string normalize (ssize_t len = -1, GLib.NormalizeMode mode = GLib.NormalizeMode.DEFAULT);