Allow collection option label to be a callback for dynamic child label (kristijanhusak#718)

Author: rudiedirkx

src/Kris/LaravelFormBuilder/Fields/CollectionType.php

@@ -237,6 +237,10 @@ protected function setupChild(FormField $field, $name, $value = null)
             ['attr' => array_merge(['id' => $newFieldName], $this->getOption('attr'))]
         );
 
+        if (isset($firstFieldOptions['label'])) {
+            $firstFieldOptions['label'] = value($firstFieldOptions['label'], $value, $field);
+        }
+
         $field->setName($newFieldName);
         $field->setOptions($firstFieldOptions);
 
@@ -249,7 +253,6 @@ protected function setupChild(FormField $field, $name, $value = null)
 
         $field->setValue($value);
 
-
         return $field;
     }