Simplify the top-bar title detect process

_includes/topbar.html

@@ -50,7 +50,7 @@
     <div id="topbar-title">
       {% if page.layout == 'home' %}
         {{- site.data.locales[lang].title | default: site.title -}}
-      {% elsif page.collection == 'tabs' or page.dynamic_title %}
+      {% elsif page.collection == 'tabs' or page.layout == 'page' %}
         {%- capture tab_key -%}{{ page.url | split: '/' }}{%- endcapture -%}
         {{- site.data.locales[lang].tabs[tab_key] | default: page.title -}}
       {% else %}

assets/404.html

@@ -7,8 +7,6 @@ redirect_from:
   - /norobots/
   - /assets/
   - /posts/
-
-dynamic_title: true
 ---
 
 {% include lang.html %}