The string "Ubuntu One uses a Ubuntu Single Sign-On (SSO) account, and if you don't yet have one, this process will create one for you." is passed from ubuntuone-client by DBus, so ubuntu-sso-client needs this string to arrive translated.
The string "Ubuntu One uses a Ubuntu Single Sign-On (SSO) account, and if you don't yet have one, this process will create one for you." is passed from ubuntuone-client by DBus, so ubuntu-sso-client needs this string to arrive translated.