fix the problem that file being deleted by js in orbit4-5

app/views/admin/seminars/_form_file.html.erb

@@ -1,7 +1,7 @@
 <% if form_file.new_record? %>
   <div class="fileupload fileupload-new start-line" data-provides="fileupload">
 <% else %>
-  <div class="fileupload fileupload-exist start-line" data-provides="fileupload">
+  <div class="fileupload fileupload-exists start-line" data-provides="fileupload">
     <% if form_file.file.blank? %>
       <%= t(:no_file) %>
     <% else %>