Change username placehodler in login window

[duboism]

The username placeholder in the login window is username@example.com. This let the user believe that he or she must use its email address to log in (while in fact the username is needed).

As en example, I changed my password 2 times right after creating my account because I was confused and thought I mistyped my password.

The placeholder could just be username.

[hansioan]

Done

[duboism]

Thanks for the super fast answer.