Section Fieldtype should not be listable (#2425)

* If fieldtype is section, don't return as listable

* Don't show 'Listable' option to user for Section fieldtype

src/Fields/Field.php

@@ -107,6 +107,10 @@ public function isListable()
             return true;
         }
 
+        if ($this->config()['type'] === 'section') {
+            return false;
+        }
+
         return (bool) $this->get('listable');
     }
 

src/Http/Controllers/CP/Fields/FieldsController.php

@@ -96,6 +96,9 @@ protected function blueprint($blueprint)
                 ],
                 'default' => 'hidden',
                 'width' => 50,
+                'unless' => [
+                    'type' => 'section',
+                ],
             ],
         ]);