ZF-7835: Label-Decorator produces invalid id with Array-Notation/subform and numeric indices
When using multiple elements in a subform with numeric names (ids) the label decorator will create an id like "14-label", buts thats not valid. Its also not possible to change this behavior, because its hardcoded in Decorator/Label.php:317
$decorator->setOptions(array('tag' => $tag, 'id' => $this->getElement()->getName() . '-label'));
In the input-tag of the subform-element the name of the subform itself is prepended. This should be also here.