Fix report reason selector in moderation interface not unselecting ru…

…les when changing category (#29026)

app/javascript/mastodon/components/admin/ReportReasonSelector.jsx

@@ -124,7 +124,7 @@ class ReportReasonSelector extends PureComponent {
 
     api().put(`/api/v1/admin/reports/${id}`, {
       category,
-      rule_ids,
+      rule_ids: category === 'violation' ? rule_ids : [],
     }).catch(err => {
       console.error(err);
     });