Fix for offsetting of second text segments

Was noted on issue #717 that we had a problem with the text blocks on the
later lines not quite lining up when things wrapped.

Turned out this was because when we asked the first layout its height to
determine where the second layout should begin vertically, that value included
the spacing which contributed +4 pixels that we didn't actually want. Removing
that we I found we still needed one of those pixels, hence the additional plus
one.

~~Surprisingly this broke no tests, so I'm going to dig into why that is later,
but for now wanted to capture this working change for any potential comment.~~ :grimacing: