Variable values are still requested after they are unexposed

[kh90909]

A simple way to generate this issue is to switch the Oak to config mode, in which no variables are exposed.

Even though the variables are removed from the sidebar (and thus should be removed from device_vars), their values are still being requested periodically, which results in 404 errors in the console.

Needs further investigation.

[kh90909]

Note that if the 'user mode' button doesn't bring your Oak back from config mode, it's likely because your config ROM isn't updated to the latest version of OakCore. You can update your config ROM over the serial port using the procedure given in the "to test" section of this issue.

I believe this update also happens with an Oak OTA firmware update, but I'm not sure if there's currently a way to trigger one on demand.

[kh90909]

In progress.