No allowed children - UI bug

[glombek]

If I try to only allow 2 levels of my Meganav, I believe it's possible to mark the permissions settings as "Allow chosen types" and then select no children.

This seems to work, only allowing 2 levels, but when reopening the settings, its marked as "Allow all" again.

Version 3.0.1 (but skimming the code I think it's still present in latest too)