Fix app theme being ignored for public projects

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/common.scss

@@ -350,6 +350,7 @@ table {
 .navbar-gitlab .navbar-inner .nav > li .btn-sign-in {
   @extend .btn-new;
   padding: 5px 15px;
+  text-shadow: none;
 }
 
 .broadcast-message {

app/views/layouts/public.html.haml

 !!! 5
 %html{ lang: "en"}
   = render "layouts/head", title: "Public Projects"
-  %body{class: "ui_mars application", :'data-page' => body_data_page}
+  %body{class: "#{app_theme} application", :'data-page' => body_data_page}
     - if current_user
       = render "layouts/head_panel", title: "Public Projects"
     - else

app/views/layouts/public_projects.html.haml

 !!! 5
 %html{ lang: "en"}
   = render "layouts/head", title: @project.name_with_namespace
-  %body{class: "ui_mars application", :'data-page' => body_data_page}
+  %body{class: "#{app_theme} application", :'data-page' => body_data_page}
     = render "layouts/public_head_panel"
     %nav.main-nav
       .container= render 'layouts/nav/project'