LMS: add CSRF token to register form

lms/templates/register.html

@@ -100,6 +100,7 @@
 <section class="register container">
   <section role="main" class="content">
     <form role="form" id="register-form" method="post" data-remote="true" action="/create_account" novalidate>
+      <input type="hidden" name="csrfmiddlewaretoken" value="${ csrf_token }">
 
       <!-- status messages -->
       <div role="alert" class="status message">