Fix issue when tabs and more info both displayed
Fix issue when tabs and more info both displayed

The visualisation element doesn't have enough height when tabs and
"more info" are displayed with a double-decker graph, which means
the blue bar from the top of the more info is displayed in an
odd place.

keithiopia/spotlight,tijmenb/spotlight,keithiopia/spotlight,alphagov/spotlight,tijmenb/spotlight,keithiopia/spotlight,alphagov/spotlight,tijmenb/spotlight,alphagov/spotlight