Remove "you" word.

Author: armetiz

UPGRADE-2.1.md

@@ -161,7 +161,7 @@
 
  * The custom factories for the firewall configuration are now
  registered during the build method of bundles instead of being registered
- by the end-user. This means that you will you need to remove the 'factories'
+ by the end-user. This means that you will need to remove the 'factories'
  keys in your security configuration.
 
  Before: