Code review comment for lp://qastaging/~mardy/unity-scope-click/signon-plugin

> Why is this change required?

Because the token name is a runtime parameter that depends on the hostname (therefore, we cannot put it in the <template> element of a .service file).
Of course, the root reason is that I made the TokenName a required parameter of the new signon-plugin-ubuntuone authentication plugin; another option is that we make it optional, and make the authentication plugin build the default value itself.

Let me know, if that's how you'd prefer it to be done (I think it's much cleaner like this, but indeed it causes more changes around).