Admin login is looking for en.yml keys for placeholder text

English i18n YAML file is missing keys found in the French. As a result, the admin login screen is showing
HTML errors from placeholder text that does not translate.

![publify login showing errors from missing en.yml](https://f.cloud.github.com/assets/743877/1264388/10576392-2c5f-11e3-802d-826bd84eb232.png)