This may become a warning rather than an action later, but for now
let's make sure older installations that had incorrect permissions
are taken care of.
This is a stop-gap CSRF protection mechanism from unsophisticated attacks. It's to be considered a temporary solution until a more complete one can be implemented, but it should be sufficient in most cases for the time being.
See https://github.com/tonarino/innernet/issues/38 for further discussion.