Fix #6717: Do not double html-encode page titles (#6720)

app/views/layouts/application.html.haml

@@ -11,7 +11,7 @@
     %meta{ name: 'theme-color', content: '#282c37' }/
     %meta{ name: 'apple-mobile-web-app-capable', content: 'yes' }/
 
-    %title= content_for?(:page_title) ? safe_join([yield(:page_title).chomp, ' - ', title]) : title
+    %title= content_for?(:page_title) ? safe_join([yield(:page_title).chomp.html_safe, title], ' - ') : title
 
     = stylesheet_pack_tag 'common', media: 'all'
     = stylesheet_pack_tag current_theme, media: 'all'