[folks] telepathy: Set _prepare_pending to true at beginning of prepare. Fixes folks init unit test failure.

[Jeremy Whiting <jpwhiting src gnome org>]

commit 91e9b0d9258155cb6e8a4a7af83a890f65e861b7
Author: Jeremy Whiting <jpwhiting kde org>
Date:   Fri Jul 13 10:59:39 2012 -0600

    telepathy: Set _prepare_pending to true at beginning of prepare.
    Fixes folks init unit test failure.

 backends/telepathy/tp-backend.vala |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/backends/telepathy/tp-backend.vala b/backends/telepathy/tp-backend.vala
index e0a3293..c0fff83 100644
--- a/backends/telepathy/tp-backend.vala
+++ b/backends/telepathy/tp-backend.vala
@@ -98,6 +98,7 @@ public class Folks.Backends.Tp.Backend : Folks.Backend
 
           try
             {
+              this._prepare_pending = true;
               this._account_manager = AccountManager.dup ();
               yield this._account_manager.prepare_async (null);
               this._account_manager.account_enabled.connect (