Wp-calypso: Site View and "Admin" bylines

[fraying]

Two problems with the Site View and Admin bylines. For example: https://wordpress.com/read/blogs/118534215

1. We shouldn't show "by admin" in the header. If the name is "Admin" there, we should hide the whole byline here like we do in cards.

2. In the cards, because we're hiding "Admin" and the site name, there's a blank line at the top of every card. That blank line should be omitted.

So it should look like this:

[mknepprath]

@fraying I've created a PR for this issue if you'd like to look it over: #13546

Thanks! :)

[fraying]

@mknepprath Woot! Thank you.