Revert "Inform when we make a bad password (not new i18n)"

On the next mail check, the user will be asked for the password
again, since we set mAskAgain to true.
In addition, the error message is shown by AkonadiTray, like
any other error message from Akonadi.

BUG: 281935
This reverts commit 38af197f.
(cherry picked from commit 981b0f7c)