Fixing missing and translation lines

Fixed messages on registration finish page. Messages there could not be
translated as they were not updated to newest versions of messages from
yii2-user/views/registration/finish.php
I'm guessing that whenever messages in
yii2-user/views/registration/finish.php were changed, they were not
updated in language files.
fixing double dots in messages

Messages on registration finish page had double dots. Removed ones in
translation files at it looks like that rest of translation files are
w/o dots.
Merge pull request #146 from sosojni/master

Fixing missing translations