[folks] For Vala 0.12, don't use deprecated string.to_int().

[Travis Reitter <treitter src gnome org>]

commit be8f7259ddd1dcd558b28ffc0761358e8d49bd48
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Thu Feb 3 11:38:05 2011 -0800

    For Vala 0.12, don't use deprecated string.to_int().

 backends/key-file/kf-persona-store.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/backends/key-file/kf-persona-store.vala b/backends/key-file/kf-persona-store.vala
index 4a3d1a4..8b169f9 100644
--- a/backends/key-file/kf-persona-store.vala
+++ b/backends/key-file/kf-persona-store.vala
@@ -228,7 +228,11 @@ public class Folks.Backends.Kf.PersonaStore : Folks.PersonaStore
               var groups = this._key_file.get_groups ();
               foreach (var persona_id in groups)
                 {
+#if VALA_0_12
+                  if (int.parse (persona_id) == this._first_unused_id)
+#else
                   if (persona_id.to_int () == this._first_unused_id)
+#endif
                     this._first_unused_id++;
 
                   Persona persona = new Kf.Persona (this._key_file, persona_id,