[vala] glib-2.0: Allow null as argmument for string.escape()

[Rico Tzschichholz <ricotz src gnome org>]

commit 4094b053d612dfa0156571be2e621424290e97ff
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Sep 20 12:08:09 2016 +0200

    glib-2.0: Allow null as argmument for string.escape()

 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 fc90df4..a2a315c 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -1039,7 +1039,7 @@ public class string {
        [CCode (cname = "g_strconcat")]
        public string concat (string string2, ...);
        [CCode (cname = "g_strescape")]
-       public string escape (string exceptions);
+       public string escape (string? exceptions = null);
        [CCode (cname = "g_strcompress")]
        public string compress ();
        [CCode (cname = "g_strsplit", array_length = false, array_null_terminated = true)]