Terran add-ons have an overly large footprint_radius

[eminence]

The Terran add-on buildings (like the barracks reactor) report an overly large footprint_radius in the returned AbilityData from the game. Here's an example (in json format):

  {
    "ability_id": 422,
    "link_name": "BarracksAddOns",
    "link_index": 1,
    "button_name": "Reactor",
    "friendly_name": "Build Reactor Barracks",
    "hotkey": "C",
    "remaps_to_ability_id": 3683,
    "target": "PointOrNone",
    "available": true,
    "allow_minimap": false,
    "allow_autocast": false,
    "is_building": true,
    "footprint_radius": 3.5,
    "is_instant_placement": true,
    "cast_range": 0.0
  }

I'm not sure if the correct value should be 1.0 (for the add-on only), or maybe 2.5 (if including the footprint of the barracks)