select immerda.ch by default

app/views/signup/create.html.erb

@@ -9,7 +9,7 @@
     </td><td>
       @
     </td><td>
-      <%= select_tag :domain, options_for_select(@domains.map{|d| [d,d]}) %>
+      <%= select_tag :domain, options_for_select(@domains.map{|d| [d,d]}, 'immerda.ch') %>
     </td></tr>
     <tr><td>
         <%= label_tag(:new, (t :new_pw)) %>

app/views/users/new.html.erb

@@ -4,7 +4,7 @@
     <tr><td><%= label_tag(:alias, (t :alias)) %></td>
       <td><%= text_field_tag(:alias, @the_user['alias']) %></td></tr>
     <tr><td><%= label_tag(:domain, (t :domain)) %></td>
-      <td><%= select_tag :domain, options_for_select(@domains.map{|d| d['domain']}, @the_user['domain']) %></td></tr>
+      <td><%= select_tag :domain, options_for_select(@domains.map{|d| d['domain']}, @the_user['domain'] || 'immerda.ch') %></td></tr>
     <tr><td><%= label_tag(:forward, (t :forward)) %></td>
       <td><%= text_field_tag(:forward, @the_user['forward']) %></td></tr>
   <% if params[:forward].present? %>