[FIX] mail: hide im_status RPC

If the `/longpolling/im_status` route is slow to respond, the UI might
be blocked while there is no good reason to do it.

closes odoo/odoo#33643

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/js/services/mail_status_manager.js

@@ -89,6 +89,8 @@ MailManager.include({
         return this._rpc({
             route: '/longpolling/im_status',
             params: { partner_ids: partnerIDs },
+        }, {
+            shadow: true,
         }).then( function (results) {
             self.updateImStatus(results);
         });