revert invoking customHeader()

src/server/views/layout/layout.html

@@ -12,6 +12,8 @@
 
   <meta name="apple-mobile-web-app-title" content="{{ appTitle() }}">
 
+  {{ customHeader() }}
+
   {% include '../widget/headers/favicon.html' %}
   {% include '../widget/headers/ie11-polyfills.html' %}