how to set the connection.permissions to empty for all new connections

[Jelle de Jong <jelledejong powercraft nl>]

Hello everybody,

I want my users to make wifi connections and have them automatic connect 
without the having to be login first, so I want the connection to be 
shared across all users.

It is my understanding that the connection.permissions is preventing 
this when it is set:

permissions=user:jdoe:;

How can I change the network manager default to not sent any permissions 
for new connections created?

Kind regards,

Jelle de Jong