[FIX] web_analytics: missing explicit empty value for WebClient.subscribe_deferred

bzr revid: odo@openerp.com-20130124124132-6xgqf9qy22kkxasn

addons/web_analytics/static/src/js/web_analytics.js

@@ -270,6 +270,7 @@ openerp.web_analytics = function(instance) {
         // client does not already exists, we are in monodb mode
         instance.web.WebClient.include({
             start: function() {
+                this.subscribe_deferred = $.when();
                 var d = this._super.apply(this, arguments);
                 this.tracker = new instance.web_analytics.Tracker();
                 return d;