Use the target for file notifications

The node is not yet accessible if you did not accept the share yet.
So trying to get it results in an acception.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

apps/files_sharing/lib/Notification/Notifier.php

@@ -176,7 +176,7 @@ class Notifier implements INotifier {
 					'share' => [
 						'type' => 'highlight',
 						'id' => $notification->getObjectId(),
-						'name' => $share->getNode()->getName(),
+						'name' => $share->getTarget(),
 					],
 					'user' =>  [
 						'type' => 'user',
@@ -212,7 +212,7 @@ class Notifier implements INotifier {
 					'share' => [
 						'type' => 'highlight',
 						'id' => $notification->getObjectId(),
-						'name' => $share->getNode()->getName(),
+						'name' => $share->getTarget(),
 					],
 					'group' => [
 						'type' => 'user-group',