well it wasnt like this on stock gb and ics. started to seen like this after cm10 rom. anyway its not a big deal but i just want to edit or delete it if its possible.
you can try install xposed framework, then install gravity box for JB. there is a setting for lockcreen where u can add a custom provider text. simply write a emty space ( " " ) in it - done. remember to reboot after installing the framework from its app. after then insatll the gravity box module & check in modules, again reboot. now do ur stuff.