#18 hold-position sign does not change color if unit is off duty

[Felix]

If a unit is sent to a specific position a purple circle appears. This sign does not lose its color (respectively becomes grey), if this unit is set off duty (cf. home sign where the behavior is proper).

[Robert W]

discussed with Felix:
HoldPosition is an order, AtHome is just a stat.
So different behaviour of the color is better