Error f:all ignors editable: false on renderAssociationInput in method renderDefaultInput

[editableIgnoreOnRenderAssociationInput.zip](https://github.com/grails-fields-plugin/grails-fields/files/1058208/editableIgnoreOnRenderAssociationInput.zip)
grailsVersion=3.1.4
fields: 2.1.5

In the dynamically scaffolded domain class 'TestConstraint'

```
package editableignoreonrenderassociationinput

class TestConstraints {
String dontBeEditable
SelectObjects dontBeEditableEither

static constraints = {
dontBeEditable editable: false
dontBeEditableEither nullable: true, editable: false
}
}

```

the select field 'dontBeEditableEither' with the constraint 'editable: false'
is still editable in edit and create view.
The text field 'dontBeEditable' isn't editable as expected.

Use the attached reproduction with Grails 3.1.4 and fields 2.1.5 as the starting point. Inspect renderAssociationInput and renderDefaultInput, comparing the association field with the text field when editable: false is set. Done means dontBeEditableEither is no longer editable in the dynamically scaffolded create and edit views.

Written by the indexing model from the issue text.