[IMP] remove [Invalid Username or Password] note as soon as a new login is submit, don't wait for page reload while checking for login correctness

lp bug: https://launchpad.net/bugs/921575 fixed

bzr revid: xmo@openerp.com-20120130115255-dt39hk25ri9u0whu

addons/web/static/src/js/chrome.js

@@ -621,6 +621,7 @@ openerp.web.Login =  openerp.web.OldWidget.extend(/** @lends openerp.web.Login#
      */
     do_login: function (db, login, password) {
         var self = this;
+        this.$element.removeClass('login_invalid');
         this.session.on_session_invalid.add({
             callback: function () {
                 self.$element.addClass("login_invalid");