fix(Upload): Fix Upload Torrent can't save in database

In old version , when save torrent in database the onwer_id will get from app()->session.
However, in commit 4258e5f ,
We remove user info from session and use app()->user to get curuser object.
But This Line is forget to change and will raise this Error when upload torrent:
`SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'owner_id' cannot be null`

apps/controllers/TorrentsController.php

@@ -46,7 +46,7 @@ public function actionUpload()
                 try {
                     $torrent->flush();
                 } catch (\Exception $e) {
-                    return $this->render("errors/action_fail.html.twig", ['title' => 'Upload Failed', 'msg' => $torrent->getError()]);
+                    return $this->render("errors/action_fail.html.twig", ['title' => 'Upload Failed', 'msg' => $e->getMessage()]);
                 }
 
                 return app()->response->redirect("/torrents/details?id=" . $torrent->id);

apps/models/form/TorrentUploadForm.php

@@ -147,7 +147,7 @@ public function flush()
         app()->pdo->beginTransaction();
         try {
             app()->pdo->insert('torrents', [
-                'owner_id' => app()->session->get('user')['id'],  // FIXME it's not good to get user by this way!!!!!
+                'owner_id' => app()->user->getId(),
                 'info_hash' => $this->info_hash,
                 'status' => $this->status,
                 'title' => $this->title,