Set Restricted Restore option to uncheck by default since it's experimental

In WHM backup restore page, the "Restricted Restore" is checked by default. Since this is experimental, it should not be selected by default.

Note: Restricted Restore performs additional security checks on the backup file. If a component of the backup file has a security issue, the system will not restore that portion of the backup.

Restricted Restore is experimental and should not be considered an effective security control at this time. It is intended to allow restoring backups from untrusted sources in a future release. cPanel strongly recommends that you do not restore data from anyone whom you would not trust with root access to the server.

For more information, see: http://go.cpanel.net/insecurerestoreaccount