NOTE: Perform tests with Debug Mode turned "on" and "off".
# Preparations
# login to Admin Console as `root`
# go to {nav User Management > Administrators} section
# create administrator
# Part 1
* in Database:
# set `IPRestrictions` column for `admin` user group to `NULL`
* in Admin Console:
# login to Admin Console using above created administrator account
# confirm, that login was successful
# Part 2
* in Database:
# set `IPRestrictions` column for `admin` user group to an empty string
* in Admin Console:
# login to Admin Console using above created administrator account
# confirm, that login was successful