Add timeout method to force call of idle to send ping

plugins/Msn/msnmanager.php

@@ -76,6 +76,14 @@ class MsnManager extends ImManager {
         }
     }
 
+    /**
+     * Message pump is triggered on socket input, so we only need an idle()
+     * call often enough to trigger our outgoing pings.
+     */
+    function timeout() {
+        return $this->pingInterval;
+    }
+
     /**
      * Process MSN events that have come in over the wire.
      *