Merge pull request ppy#11137 from nanaya/reportable-user-id

Fix null user id error when reporting old (imported) comments

Author: notbakaneko

app/Models/Comment.php

@@ -302,7 +302,7 @@ protected function newReportableExtraParams(): array
     {
         return [
             'reason' => 'Spam',
-            'user_id' => $this->user_id,
+            'user_id' => $this->user_id ?? 0,
         ];
     }