[vala/staging] glib-2.0: Add binding for "warning_once()" since 2.64

[Rico Tzschichholz <ricotz src gnome org>]

commit af96bf8c05c76e4bae2b8b55def9a256f22c70aa
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Oct 16 13:44:40 2019 +0200

    glib-2.0: Add binding for "warning_once()" since 2.64

 vapi/glib-2.0.vapi | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index fde96b877..111774e57 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -2599,6 +2599,10 @@ namespace GLib {
        public void warning (string format, ...);
        [Diagnostics]
        [PrintfFormat]
+       [Version (since = "2.64")]
+       public void warning_once (string format, ...);
+       [Diagnostics]
+       [PrintfFormat]
        public void critical (string format, ...);
        [Diagnostics]
        [PrintfFormat]