fix: Fix logic error

src/web/pages/templates/_layout.html.j2

@@ -5,7 +5,7 @@
     <meta charset="UTF-8" />
     <title>{% block title %}Continuwuity{% endblock %}</title>
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    {%- if allow_indexing %}
+    {%- if !allow_indexing %}
     <meta name="robots" content="noindex" />
     {%- endif %}