Fix translations of hostpref_nickname_title.

- German translation was "username".
- French translation was "family name".

I changed them to the translation of just "name" (not "nickname"), as
this is what Android uses in VPN settings.
Change text and some translations of hostpref_nickname_title to "name".

I changed them to (the translation of) just "name" (not "nickname"), as
this is what Android uses in VPN settings.