SEC-1207. Fixed class name in jsp

samples/cas/client/src/main/webapp/casfailed.jsp

@@ -11,7 +11,7 @@
 
 <font color="red">
     Your CAS credentials were rejected.<br/><br/>
-    Reason: <%= ((AuthenticationException) session.getAttribute(AbstractProcessingFilter.SPRING_SECURITY_LAST_EXCEPTION_KEY)).getMessage() %>
+    Reason: <%= ((AuthenticationException) session.getAttribute(AbstractAuthenticationProcessingFilter.SPRING_SECURITY_LAST_EXCEPTION_KEY)).getMessage() %>
 </font>
 
 </body>