You should go to your Database from your Hosting and go to table : "ps_configuration" and look for column "name" with the value : PS_MAINTENANCE_IP and from there you can remove the IP Adresse you want.
You should go You Database from your Hosting and go to table : "ps_configuration" and look for column "name" with the value : PS_MAINTENANCE_IP and from there you can remove the IP Adresse you want.