[10.18] public player deleting player stop bug

[ӔO]

There seems to be an odd bug, where the physical stop will be deleted, but the stop itself will remain.

to reproduce:
1. as a player, build a stop.
2. switch to public and delete player stop
3. stop will have been deleted, but name and coverage will remain

This stop can be built over by the same player, but the two stops will be considered physically different, even if they occupy the exact same space

as an addition, if there are two stops within walking distance, and the public player deletes one of those stops, simutrans will crash.
1. open backup2 save from server game
2. switch to public player
3. delete axhall railway station as public player
4. game will crash

oddly, the game will not crash if the bus stop is deleted

[jamespetts]

I have found and fixed the first described but on the 10.x branch, which would very probably have given rise to the second bug. Thank you for the report!