Update app.js

Hi, When I am using event "request+action" and returing  false,  "loading message" doesn't hide.

for example:
 rcmail.addEventListener('requestlist',function(q){
      var response=cachelist.get(q._mbox,q._page)
      response.unlock=q._lock;
      rcmail.http_response(response);
      return false;
}
////////////
if response has not  "unlock" , system doesn't hide 'loading message' and all interface is  seting  busy