Registering New User : No successful activation message

While registering new user, the browser tab does not show a successful activation message on clicking the activation link in the email.

Expected result: The browser tab must display a message like "You can now log into Zanata".

Actual result: A new browser tab with login screen opens. Screenshot attached.

Server log :

2015-06-18T05:56:56,389Z INFO (default task-2) persist entity: HAccount(super=HAccount@9ba654a1, username=logintest)
2015-06-18T05:56:56,390Z INFO (default task-2) Account logintest created
2015-06-18T05:56:56,459Z INFO (default task-2) persist entity: HPerson(super=HPerson@dc4e3d98, name=Login test)
2015-06-18T05:56:56,465Z INFO (default task-2) get register key:a21014ae64058972839f6f430cc6e6d6
2015-06-18T05:56:56,524Z INFO (default task-2) Sending message with Subject "Zanata Account Activation" to Recipients From Reply-To