Description of problem:

The activation key should update after user click "Resend activation email".
Otherwise after activation key expired, the user won't be able to activate himself/herself as he/she still get the old activation key, which is still expired.

Version-Release number of selected component (if applicable):
2.2.1-SNAPSHOT (20130301-0034)

How reproducible:
Always

Steps to Reproduce:
1. Register a new user, but ignore the activation email.
2. Make the activation key expired by either change the database record, or wait for 24 hours.
3. Sign in
4. Click "Resend activation email"
5. In email client, click the activation link in new email.
  
Actual results:
Activation link expired. Please sign in and click "Resend activation email". 

Expected results:
User activated.

Additional info: