Save last IP ban expiry duration

Hello,
the checkbox "Save last IP ban expiry duration" affects to the default expiry duration only.

Case, when the checkbox is disabled.

• You set default expiry duration as "1 day"
• You ban a few IPs and set "1 week" duration (not default value) and need to change the expiry value from default one
• If you don't want to do the changing every time you need to go to the Settings Form, change default expiry duration value to "1 week"

The checkbox automates the work. If the checkbox is enabled the default expiry duration will be changed automatically and you can do IP ban series without changing the default expiry duration value at the Settings Form.