Hide tab-bar in login-box when only one tabs is shown.

app/views/devise/shared/_signin_box.html.haml

@@ -7,6 +7,7 @@
       %h3 Sign in
   .login-body
     - if form_based_providers.any?
+      - if form_based_providers.count >= 2 || signin_enabled?
         %ul.nav.nav-tabs
           - if crowd_enabled?
             %li.active
@@ -27,6 +28,13 @@
           - if signin_enabled?
             %div#tab-signin.tab-pane
               = render 'devise/sessions/new_base'
+      - else
+        - if crowd_enabled?
+          = render 'devise/sessions/new_crowd'
+        - elsif @ldap_servers.any?
+          = render 'devise/sessions/new_ldap', server: @ldap_servers.first
+        - elsif signin_enabled?
+          = render 'devise/sessions/new_base'
 
     - elsif signin_enabled?
       = render 'devise/sessions/new_base'