Now from release 3.21 we have this feature.To disable the WiFi, go to "network" page, click "advanced setting", you will find a field "WiFi Enabled/Disabled:", set it on disabled and click "submit".The WiFi will be disabled.In case the system restart due to power outage, the WiFi will be enabled as Access Point for 3 minutes and then will be disabled. The 3 minutes (180 sec) is given by the other setting in the same page "Access Point time (sec):" you can modify also this parameter according to your needs.
Now from release 3.21 we have this feature. To disable the WiFi, go to "network" page, click "advanced setting", you will find a field "WiFi Enabled/Disabled:", set it on disabled and click "submit". The WiFi will be disabled. In case the system restart due to power outage, the WiFi will be enabled as Access Point for 3 minutes and then will be disabled. The 3 minutes (180 sec) is given by the other setting in the same page "Access Point time (sec):" you can modify also this parameter according to your needs.