Fix: #6089 - Cannot Add New Users due to incorrect array structure

[TheWitness]

This fixes the defect introduced in d9ea74f and corrects array structure where it had been modified.

[netniV]

I don't think this fix goes the right way. We should not be returning two different structures of array from a single small function like this.

[TheWitness]

It's always been a two dimensional array

realms = array(
id1 => name1,
id2 => name2,
...
);

You made a change to add the 'selected' and 'name' attributes to set the default selected on the backend and added those two attributes. It's the only place on Cacti that it's done. So, I would prefer we just use this. We don't need to be doing major re-designs in the 1.2.x branch.

[TheWitness]

@netniV, please re-review. I'm okay keeping with a single function for the moment. I don't want to invest too much time in 1.2.x at this point.