[2.1.17] Wrong platform movement direction after turning around

[flomz]

I had encountered this bug on versions before 2.1 as well.

Prerequisites:
- Space platform orbiting planet A
- No active schedule
- Automatic thrust mode
- Enough fuel

Steps:
- Create a new schedule, add a single planet B (platform starts moving immediately)
- Let the platform to speed up to, say, 200km/s
- Before platform reaches 7000 km mark, delete active schedule (Destination planet, as is shown below the map, switches from B to A. Platform is slows down, but still moves toward B unless it slows below 0 km/s. So far so good)
- While between planets, create a new schedule, add planet A (platform starts speeding up towards A)
- After letting the platform to speed up, delete active schedule.

Expectation:
- Platform continues moving towards A, slowing down rapidly
- If speed is shown as positive, destination (as is shown below map) should be A.

Observation:
- Platform immediately switches direction and moves towards B, slowing down rapidly.
- Speed is positive, destination is shown as A, as it should be.


So if I decide to turn around mid-journey and decide to save some fuel by deleting active schedule at 14500 km mark, i suddenly start moving away from destination planet. Manually turning engines off instead of deleting active schedule works without issues.