[5.10 HF3] Minor bug when selecting and de-selecting normal/Super Highway exits via the HUD

[Sparky Sparkycorp]

If you left-click on a Super Highway exit, it will change colour and be the playership's target (WAI).

If you then de-select it by mouse-clicking in empty space, the exit icon is replaced by the targetting box for an L combat ship (big).

This is reversible by re-clicking on the exit icon, and then again in empty space (ship icon reverts to the highway icon).

Observable in the following save:

https://drive.google.com/file/d/1kLxty2 ... sp=sharing

Edit: Also applies to regular highways.