Fixed typo in upgrade file

Author: XWB

Upgrade.md

@@ -10,7 +10,7 @@ Methods and properties removed from `FOS\UserBundle\Model\User`
 
 - `$expired`
 - `$credentialsExpired`
-- `setExpired()` (use `setExpireAt(\DateTime::now()` instead)
+- `setExpired()` (use `setExpiresAt(\DateTime::now()` instead)
 - `setCredentialsExpired()` (use `setCredentialsExpireAt(\DateTime::now()` instead)
 
 You need to drop the fields `expired` and `credentials_expired` from your database