Fix display of email address on 404 pages

lms/templates/static_templates/404.html

@@ -4,5 +4,5 @@
 
 <section class="outside-app">
   <h1>Page not found</h1>
-  <p>The page that you were looking for was not found. Go back to the <a href="/">homepage</a> or let us know about any pages that may have been moved at <a href="mailto:technical@edx.org">technical@edx.edu</a>.</p>
+  <p>The page that you were looking for was not found. Go back to the <a href="/">homepage</a> or let us know about any pages that may have been moved at <a href="mailto:technical@edx.org">technical@edx.org</a>.</p>
 </section>