Impossible to edit some containers

60 r24927

I get the attached ClassCastException when I try to edit a box.
It seems to be a consequence of commit 24923 (JahiaContainerStructure.getObjectDef() cast as JahiaFieldDefinition):

private static boolean hasPageField(JahiaContainer container) throws JahiaException {
for (Iterator<JahiaContainerStructure> structureIterator = container.getDefinition().getStructure(); structureIterator.hasNext() {
JahiaContainerStructure field = (JahiaContainerStructure) ((Iterator) structureIterator).next();
JahiaFieldDefinition fieldDefinition = (JahiaFieldDefinition) field.getObjectDef();
if (fieldDefinition.getType() == FieldTypes.PAGE)

{ return true; }

}
return false;
}