Avoid recover PULL messages for NULL UA
Avoid recover PULL messages for NULL UA

frsela/notification_server,telefonicaid/notification_server,frsela/notification_server,telefonicaid/notification_server,frsela/notification_server,telefonicaid/notification_server,frsela/notification_server,frsela/notification_server,telefonicaid/notification_server,telefonicaid/notification_server