Use deface in wiki plugin

app/views/admin/configs/_tab_others.html.haml

@@ -1,5 +1,3 @@
-- if defined? FoodsoftWiki # avoid requiring deface here (the single exception)
-  = config_input form, :use_wiki, as: :boolean
 = config_input form, :use_nick, as: :boolean
 = config_input form, :tolerance_is_costly, as: :boolean
 = config_input form, :disable_invite, as: :boolean

app/views/sessions/new.html.haml

@@ -10,9 +10,6 @@
   .alert.alert-error
     != t '.nojs', link: link_to(t('.noscript'), "http://noscript.net/")
 
-- if defined?(FoodsoftWiki) && (page = Page.public_front_page)
-  = wikified_body page.body, page.title
-
 = form_tag sessions_path, class: 'form-horizontal' do
   .control-group
     %label(for='nick' class='control-label')